Lil, using multiple double-pointed needles is exactly the same as knitting in the round on circular needles. You just use the DP needles for when you're knitting something in the round that is too small to manage on circular needles. It's not hard at all!
Some folkways use 3 needles, some use 4, some use 5. I learned with 4, so that's what I use. When knitting socks, where you have to make a heel flap and then knit it back into the instep, you do go to two of the four needles to do that, and then, by doing increases, work your way back to 4 needles and knit the rest of the way down in the round again, decreasing toward the toe. (And, if you were making socks for my husband, increasing for his bunions, which is why custom made socks are so great.)
It's not at all as hard as writing it out sounds. It's a bit more complicated than crochet, but doesn't use as much yarn because you're not wrapping the yarn for the most part.
I can crochet and have made a few afghans and a very lacy baby layette, but mostly I use crochet when needed in knitting (It's a handy skill to have if you knit, especially as a beginner, as it's great for picking up dropped stitches.)
Purling is no big deal. It's just entering the stitch from the other side and pulling the yarn through from that side. Nothing to be afraid of.
Just practice your gauge square with the stitch pattern you'll be using as many people don't purl to the same gauge that they knit.
