I wear jerseys for the pockets and moisture wicking. They do make shorter shorts. I don't have any and you wouldn't want to see my legs in them, but my friend has a pair and I've seen others. Not real common, but they're out there.

Cadence is how fast you are spinning. RPM or revolutions per minute. If you are at a 90 rpm cadence, you are spinning your pedal 90 times in a minute. You need a bike computer with a cadence sensor to know what your cadence is, but depending on what your goals are, you don't need it.

Everyone rides a bike for different reasons. Some want to get as fast as they can and maybe race, others don't care about speed, but go for distance, others just enjoy getting out and smelling the roses ... as well as the people who are somewhere in between, like maybe you are. You don't have to have a bike computer and a jersey to be serious about cycling. For me, getting stronger, working on my speed, being able to keep up with club members and do well at an event is what gets me excited about going out and riding. Sometimes I like to ride just to ride and enjoy the scenery, but I'm on a high when I get back from a ride that I rode faster than I ever have before.

To each his own. As long as you are happy riding a bike, you don't need to do anything different than what you are doing.