The pain in your sit bones will go away as you ride more. I don't understand why this is, but if I'm off the bike for a few weeks I'll experience it again during the first ride back. Chafing is another issue and something will have to change to resolve it. Avoid seams and stuff that moves around as you pedal. Proper bike shorts/bibs are optimal as they are designed for the purpose. Probably not needed for the distances you are contemplating but don't rule out trying them if your issues continue.
Last edited by shelbyfv; 10-30-20 at 11:10 AM.
Reason: sp