Are there dual pilot planes to pilot myself? I understand planes have 2 piloting systems often?

Is there a plane I can demo fly first flight?

I'm interested in saying I have flown and that's it.
Yes, the vast majority of airplanes have dual controls. You can just call up your local flight school and explain what you want. A "Discovery Flight" is typically 30 minutes of flying, just to see if you're interested, but if you want to go for longer than that, just let them know beforehand.