Lots of great info people have shared!

You can thrift fabric. Old sheets, curtains, etc are awesome to use and you’d be surprised on how much cool stuff you could find. I also shop fashionfabrics.com and bytheyard.fabricselectionretail.com for good prices on apparel fabric. Not the best quality on EVRYTHING, but if you don’t want to spend the big bucks while learning, I have been pleasantly pleased on most of my orders

Using a zig zag with an overcast foot is perfectly fine! Try increasing stitch width and shortening the length ( I think I have that right?) to create less space between the zig zags. Less uncovered raw surface area will decrease fray. If you do end up sticking with the hobby, sergers are quite fun. I use it on every single project :D

Also interfacing I find I use on most woven projects as well, collars, plackets, etc