Searching "free bjd clothing patterns" yields a lot of stuff. DeviantArt even seems to be a good resource for some free patterns.
Most of the free stuff is just basic things, but they're a good starting point and you can embellish and add whatever you like to them.
Unless you're pretty skilled with a sewing machine, I would start with hand sewing. Learn how to do a nice, solid backstitch and how to properly tie off and you should be pretty golden as long as you're not sewing through a lot of denim.