Different mild steels?


I have been beating steel for a few weeks now and I started with some scrap steel that I picked up form a machine shop. I am attempting to make the little leaf hooks and such. So the other day I purchased some .5" hot roll form a local supplier and it seems to be very less forgiving and harder to work than whatever kind of steel the scrap was.
I can’t seem to find anything that talks about different kinds of mild or what kind of stock I should look for to do these kinds of projects. Lots of write ups about blade steels but nothing aside from size suggestions for mild / hooks and such.
What should I look for? Are there online suppliers I should look at?
Thanks in advance