In the video below, I cover four different ways you can attach Kato Unitrack tor your layout project. You can nail or screw your track down, use hot glue, latex caulk, and regular PVA (e.g. elmer’s) glue.
Screwing Unitrack to your layout base is a viable option for T-Trak or similar small modules where you can lay the module on its side and more easily line up the screws and the holes on the bottom of the track. If you drill out the holes through the top of the track, you can use small track nails to hold the track down, assuming you have a wooden base for your track.
If physical attachment methods aren't viable, or you don't want to see nail heads, gluing your track down is the best option. Hot glue works great, but you have to be careful to keep your track level and not get too much under your rail joints where it can cause uneven joints.
Latex caulk is a great adhesive for track. Just spread it smooth and the quick grab of the caulk makes it easier to use than regular white/PVA type glue. But, using regular glue will work nice as long as you are able to keep your track from shifting during the longer dry time of that type of adhesive.
You can watch the video going over all the methods below.