To have fun with a train set, you need to mount the track on something. This guide gives some ideas for easy and inexpensive track mounting. You may not have a hobby store nearby, so I will include things you can get in other stores.

Track is usually mounted using track nails, which are tiny nails about a half inch long. One possible substitute for track nails are  the pins that are sold in the sewing section of a large store. They are the right thickness and have the right size head. But they are about an inch long, so you will need to mount on something deeper if you use pins. Another possibility is to use glue or double sided tape so you don't have to stick nails or pins into anything.

You can't push track nails or pins directly into a hard surface such as plywood. You need something softer. I looked around in a home improvement store, and my favorite is foam insulation board. It comes in a variety of thicknesses, and it comes as plain foam or with a surface layer of something denser than foam. Another option is a sheet of the soft material used in dropped ceilings. Another option is to flatten used cardboard cartons and glue about five layers together. Five layers gives enough depth that track nails won't come through.

One question you need to ask yourself is whether your layout can stay laying down flat, or whether you will need to stand it up against a wall when you are not using it. If it needs to stand up for storage, then you will need a stiffer base than if it can stay down flat. For a stiff base, you can use a thick foam insulation board or multiple layers of foam board. Or you can fasten a thin layer of foam board to something stiffer, like a piece of plywood. If you are doing N scale, one good possibility is to fasten it to the top of a cheap plastic table with folding legs.

Another approach is to fasten the track to the surface instead of sticking nails or pins into something. There are various glues that can be used for this. A general craft glue will work, or a glue gun. If you use a glue gun, low temperature glue is better than high temperature because is it less likely to deform the plastic ties under the track. If you are careful to use small amounts of glue, you can get a nice looking result. You don't need to glue a lot of places, just a couple of little spots on each piece of track. If a piece becomes loose, you can always glue a little more. But if you use too much glue, it will look ugly, and it will be hard to move the track if you decide it isn't positioned where you want it. Another easy approach is to use double stick tape. You don't need a lot of tape, just a small piece on each end of each piece of track.

Note that surface mounting does not work well with flex track. Flex track laid in a curve always tries to straighten out again, so if you tape or glue it to a surface, it will press sideways and eventually come loose. For flex track you must use track nails or pins.

If you are mounting on a table, one option is to first fasten a layer of brown shipping paper to the table. One easy way to fasten it to the table is to wrap it around the edges and use packaging tape to tape the edges to the bottom of the table. You should tape all the edges securely so the paper cannot shift around on the table.

Once you have your surface ready, before you start to lay track, you should give a base color to the surface. The least expensive way to do this is with a can of spray paint. If you use spray paint, try to do it outside on the lawn or somewhere where the over spray will not get paint on something that can be damaged. If you don't want to paint, then you may be able to find construction paper or other paper in a suitable color. Choose a color you will like as a base, usually a medium to dark green, or a brown or tan. This color represents the common grass or earth tone of the place you will be modeling. If you use shipping paper, you may be able to let its natural color be your basic earth tone.

Another thing to consider before you lay a section of track is the color you want to have under the track. Mainline track does not have green grass growing under it. It is placed on a roadbed of gravel or crushed rock, which is usually a medium to dark gray. If you are using track that includes a plastic roadbed, then it takes care of the roadbed color. But if you are using track that does not have a plastic roadbed, then you probably want to color the area under the track some suitable color. Or you can start with a base color that is dark enough to look all right under the track. This is a good approach because you can arrange your track any want you want without having to make a special color under the track.

Don't get too concerned about the exact colors at this stage. Any reasonable color will look lots better than the natural pink or aluminum color of foam board. If you use shipping paper, its natural color may be all right under the track. If you lay some track and then decide you don't like the color effect, you can take up the track and try a different color.

It is good to do some creative experimenting with colors before you lay track. If you are comfortable painting, you may want to use something like acrylic paints. My favorite way of getting colors is the chalk pastels that are sold in the craft section of a large store. They are nice because you can get varieties of shading with them, which lets you model natural earth better than you can with simple paint.

This is an area to use your creativity. If you are artistic, you can find lots of ways to get color effects. Look at natural earth and grass and foliage and look for ways to get colors that imitate those. If you are not artistic, then just do whatever gets you colors you like. Remember that in your layout, you only need to satisfy yourself, not other people. If you aren't into painting, then experiment with pastel chalk, colored construction paper, and thin foam sheets. There are lots of ways to get nice effects.

Before you lay track, decide whether you want a raised roadbed. If your track has a plastic roadbed, then the question is already answered. But if your track has no roadbed, you may want to add one. Hobby stores sell foam sheets designed to be used for roadbed. If you do not have a hobby store nearby, you can get thin foam sheets in the crafts section a large store. I have not found a good gray color, so I sometimes use black foam and rub it with white pastel chalk to make it a little more gray. I like a fairly dark black because I run steam engines, and they used to cover the roadbed with ashes and soot.

I don't think it is necessary to use roadbed in N scale. I think most of the N scale roadbed materials raise the track way too high compared to what a real railroad looks like. If you live where you can see a real track, look at it and see what the roadbed looks like. In many places, the top of the roadbed is no higher than the surrounding ground. It just has a shallow ditch on each side. For your first layout, I recommend that you not go to a lot of effort to make a roadbed. Remember that if you enjoy model railroading you will probably redesign and rebuild your layout multiple times before you get it the way you like for longer term.

The main thing is to have fun working on your railroad. Look for creative approaches that suit your personal skills and interests. Do little experiments to see what works well for you. Watch for things that you enjoy doing. Have fun!