I want to use just one part of a tile (say the bottom half) how would I do that cause godot only lets me use the whole tile

You could split the tile into quadrants, or make another tile that is only the part you want to use.

    award is there a way to do that in editor I would find that easier in some circumstances. I am going just add more tiles but i am wondering if there is an in-editor way to do that.