Paper2D tutorial not working for me

I’m a new creator, and I’m trying to learn the “in’s and out’s” of 2D before I tackle 3D. I’ve followed the YouTube guide for making a 2D platformer by Alan Noon but every time I try to drag the floor asset onto the map my character will hit invisible barriers (which I assume to be the asset) dose anyone know a solution?

Your collision on the tiles are too big maybe?
I would follow this tutorial for 2D, He explains it pretty good from what I can tell. And goes into setting collision on the tiles. or you can find the video you need about it and then go back to the one you was following.