Hi. I’m a Blender noob so forgive me if my question sounds stupid. When I’m in Texture paint mode I can’t seem to select a few parts of my mesh using shift+right click or ctrl+left click drag. It seems selected as a whole by default, but I don’t see those dotted lines when your in texture paint mode. I don’t know what to do anymore. I’m stuck. 
I never had this problem before.
Select the polys that you want to limit painting to before going into texture paint mode and on the header, select that little cube that says in the tool tip “face selection masking for painting” then you will only paint in your selection.
Thanks! I actually figured it out before my post got approved. But thanks for the help! 