If you just want to watch people play, there's tons of shows. Critical Role is the most famous - just keep your expectations for an actual game a bit lower, the people on the show are professionals and they are there primarily to make a good show and not just to have fun with each other.
They also have a series of short videos called Handbooker Helper where they explain different aspects of the game.
If you want to learn the mechanics interactively, I'd recommend you pick up Solasta: Crown of the Magister. It's a 5e based video game that explains the mechanics quite well imo. It's also played on a 3D grid, which is most likely how you will play the game irl. It's also available on Xbox Game Pass, with crossplay with Steam and a great co-op mode with up to 4 players.
Baldur's Gate 3 is coming out in early August (on PC at least), which is also based on 5e but I'm not sure how well it explains the rules. It will probably be a great RPG experience though.
Because hexagons are bestagons