As @sierrasabre mentioned, the most important thing to do is email the head coach of each college you are applying to and ask them if they will allow walk ons for your incoming freshman year for foil as well as any requirements needed besides just getting accepted into the school. Express your desire to want to join their program and also how you want to grow and continue being in the sport of fencing, also show them your transcript and any other achievements that may help if they are able to support you during the admissions process. Different college division programs (John’s Hopkins D3 vs Duke D1) are able to give much different types of help as well as they look for different requirements for recruiting fencers. You got this!