If you are going to get into this stuff you might as well do it right. Buy a 1/4# spool of B-50 bow string material, watch the string making videos on youtube, make a string jig and start making bow strings. You will need a spool of serving and a serving tool as well as some string wax.
Ebay has good prices on B-50 bowstring material with free shipping.
A string made out of paracord will rob you of a good part of your bows performance as will a string made from too many strands of any other material. I use 12 strands of B-50 for bows up to 60#.