I don't know why these connected lines aren't grouping

So I am making a mario kart track, and i want to make these lines be like 1 object so i can color it differently. Sorry if my vocabularyisn’t good, I’m new to sketchup

For example, I made a bunch of lines connecting eachother in a wierd shape, and how i want to make everything inside those lines a material, but whenever I select something inside the lines, the rest of the floor gets selected to. Is there a fix
Race.skp (302.3 KB)

Yes there is, proper use of groups and components as you are building your model will prevent this from happening. A good place to learn how to achieve this is THE LEARNING CENTER the course The Sketchup Fundamentals is the one you want.

FYI, SketchUp doesn’t have lines, it has edges.

Is there a key or a button to group them?

I watched that, and did some testing. I don’t thing that i can fill the stuff in with a material

If you create a group and everything inside it is the default color, then you can paint the whole group a color and everything in it will take on that color.

I made a group with lines though.

Let me restate. My problem is I can’t make a bunch of connected lines have a material. I can’t even select inside the lines

Sounds like you aren’t making faces successfully. I would start with the basics and work from there.