I have just noticed that my front bottom teeth are starting toget flat on the top. Is there any way to help teeth repair themselves? Rebuild enamel? Help make them stronger?

I have never been to a dentist in my life but my teeth are straight and as far as I know there are no serious issues with them. My insurance wont cover a dentist but I may go in for a cleaning soon. My school does that kind of cheap.

What can I expect them to do in a cleaning? What is it like?