Biking shouldn't hurt. If your bike fits and everything is adjusted, you could ride all day. You might be tired but not sore. The most common adjustment is raising your seat. What is sore?
It does take time to get the adjustments worked out. When I got my new bike, I went on several long rides, and each time I'd make a tiny adjustment. Toward the end it was maybe just one or two millimeters each time!
It takes me a while to wind down after a long ride.
2009 Trek 7.2FX WSD, brooks Champion Flyer S, commuter bike