You need to wash and dry the fabric before you work with it. Just throw it in the wash when you get home from the store so it’s ready when you want to use it.
These needles have a small ball on the end that prevents the needle from snagging the fabric as you sew. You can get them at your local craft or sewing shop.
Use a thread specifically for knits, or use a different stitch. I have found that it works best to sew with a very slight zig-zag stitch and use polyester thread.