Originally Posted by
DeadGrandpa
Whatever you do, don't stop riding. Make small adjustments to the saddle position and your butt will toughen up. Good luck.
And maybe only ride for a short time in a day and then gradually increase the time as you get more used to things. Being sore after 15-30 minutes is perfectly normal if you haven't ridden much before. As soon as you feel uncomfortable, get off the bike and walk around a bit. Then get back on for another however many minutes.