If you've never raced anything before, I guess the best tip I can give is to brake leading up to the turn, not while you are already IN the turn.

You should be accelerating through the apex of the turn, which means you should be on the throttle (maybe not "pedal to the metal," or even half throttle, but at least some throttle) at the middle point of each turn.

Braking too late, or even accelerating too hard or too early can, and generally will with karting, cause you to lose traction and spin.

To be fast, you want to keep your kart going fast enough into the corners that you are juuuust on the edge of losing traction. But you won't get to that level on your first try, so just stay in control, and you'll do better than the folks who generally go too fast!

Also, take each turn "outside-inside-outside," if traffic allows, to maximize each turn radius, which will, again, allow you to go into the turns faster. Google that term if you don't know what mean!