personally i like 2 layer belts, they tend to be stronger, you know, so they actually function as a belt. i always found it difficult to sew 2 ribbons together perfectly so i use stitch witchery(which i buy at walmart for $.98 a yard!), it's super easy and adds a little stiffness to the belt, which i prefer.
i bought my first sewing machine at walmart for $80, and it worked out great for developing my sewing skills. just stay away from anything mini, it's a waste of money. i didnt buy an expensive machine to begin with just in case i decided i hated sewing! my suggestion would be to buy an inexpensive full-sized machine (i also made sure it was a name brand machine like brother, white, singer etc.), it worked for me.