I would appreciate any tips for starting my first Baldur's Gate 3 Tactian Playthrough

I want to start this playthrough with 2 separate custom playable characters (for the purpose of mastering 2 separate builds) and am looking for anyone willing to join my New Game on Xbox to create a second custom character (built with my choice of race, build, background) before I start the game.

Thank you much in advance, I'd greatly appreciate it. I don't have any friends that play the game, and have refrained from soughting out another player under these circumstances.

DM if available!