Yarn shouldn't break. Go out and buy yourself a skein of inexpensive acrylic or blend for your 'starter yarn'. It doesn't have to be the cheap-o stuff. Plymouth Encore or Lion Woolease are both blends that are a decent yarn, yet not too expensive.
One of the biggest hurdles for new knitters is to keep the number of stitches even. Some lose them, some gain them. If you're doing any kind of ribbing, it's common to forget to put the yarn in the proper position for the stitch you're making--in back for knit, in front for purl. If you want, you can put a stitch marker on the needle every 10 stitches or so and keep counting.
Do yourself a favor--save the frogging for a later date. Just keep knitting. If you make a mistake, so what? Get used to knitting and purling. The more you knit, the more even your stitches will become and the more confident you'll get. Your first finished object doesn't have to be model perfect.
LOOK at your knitting. See what the knit stitches look like. Learn to recognize what happens when you purl. One of the best things you can learn, and it won't happen on your second day of knitting, is to understand the effect what you're actually doing has on the piece of work.
Hang in there. There are knitters on this forum who have been knitting for only a few months and are turning out amazing stuff. You can too!
Here's a secret----it ain't rocket science!