lonewolf, please avoid double posting, as it is against the forum rules. You can review our forum rules here. Thank you.
If you need to add more to a comment, please edit your last post and add it, rather than posting multiple times in a row.
Also, please give your threads meaningful titles. "Noob help" gives us absolutely no idea what you're having trouble with, and there are a number of reasons why it should be easy to get an idea of the general issue before even opening the thread. Please change it now - edit your first post, click on Use Full Editor, and give it a title that hints at the type of problem you're having.
Those look like wall tiles, not floor tiles, so NONE of your characters should be able to walk on them. Have you changed the passage settings of the tiles in the Tileset tab?
It's either that, or using the "change grid size" plug-in, but that comes with a bunch of other issues.
That plugin changes EVERYTHING - the collision (lets characters get closer to each other) AND the tile size. You cannot use it if you're using default sized tilesets. It is a bad idea to try to use it as a solution to this problem. That's not what it's for.
If those NPCs are drawn the same size as your character, then that's not the problem at all, as the NPCs themselves are spaced okay.
Is it all over the map, or just in that location?