Don't mind me asking, but how do you know how many rep points you have??

Look in your User CP in the top bar.

Edit: lol, yeah what neptune said.

I know that much now, but how about giving some?

If you look at the top right of every one's post, you'll see a little button with a check and an X that you use to give rep. I doubt you have any rep power at the moment though.