Nope. No need for cadence settings (at least not for most people). You need some music (the radio in your head will do fine), and to poke around with Sheldon Brown's gear calculator. You can get the gear calculator to give you your speed at various cadences, ranging from about 40 rpm on up to around 120. Spend some time puzzling out what cadence you're used to riding at. Spend some time riding like you did today, and puzzle out what cadence you can sustain right now.
Now... you've done the brain work.
It's time to get purposeful on the exercise and muscle memory end. Most people will naturally fall into time with music if some is playing or if they're singing or something. Use that. You can go totally OCD and try to find the perfect piece of music to help you with a higher cadence. Or you can do the slacker version, and just accept that most music you know goes at about 80 beats per minute or faster, and that a cadence of 80 is a tolerable spinning cadence.
Chances are you'll find that between music and your background work, you can improve your typical cadence to somewhere in the 80-90 range. If you put in effort on pedaling technique, slow speed bike handling, riding fixed, or various other technical bits, you can probably get a good deal higher. You can also get gains by focusing on the musical end, whether it's working at specific speeds, or smoothly handling changes in tempo, or doing things like pedaling at twice the tempo.
A cadence computer may help once you've hit the limits of what you can work on solo with the aid of music. Until then tho, you can't afford to watch a cadence meter all the time while you ride. And even once you've got the basics down, you may find a coach is more important than a cadence computer