It might be helpful to try both techniques yourself.

You can buy a spool at Walmart for pretty cheap, they’re often available at thrift stores for less. You’ll want to look up an “i-cord” tutorial. Any old yarn will do honestly, the acrylic super savers will work.

Nålbinding will require that you use wool. The joining process involves felting the ends together (an extra knitter might do this, but it’s not necessary - it’s okay to tie them together because you’re weaving in ends afterwards). Felting is using water and patience to shape wool. For practice, you can use a cheap plastic tapestry needle honestly - save money here because the wool is going to run you a bit more.

I find nålbinding uncomfortable and slow, personally.