Welcome from Arizona, Deedee.
If you have figures out how to enlarge the top (I assume make more blocks) you've done the hard part. Binding is easy. Just measure around the quilt and add about 18". Divide that by 42" (approximately width of fabric minus shrinkage). That's how many strips you will need for binding. Most of us use 2 1/2" strips for binding, so 2 1/2" times the number of strips is how much material you need for the binding.
Is this clear as mud? There are lots of tutorials and U-tube lessons on bindings so don't stress it. Take one step at a time and you will do fine.