New to DnD this is my first time some advice would be cool.

My friend group and I brought in a new friend and getting to know him more he told us about getting together to start a DnD campaign and so he’s the DM and out of my two other friends and I that joined only one has played a campaign so it’s a learning experience. We met last weekend and built and finalized characters and story. I’m a warlock Halfling named LeBron James. Any tips or advice you can give would be awesome. Just trying to learn this game while hanging out with good company!