Casters can be tanky. Right? I feel like min maxing allready. I don't wanna spoiler builds or anything if it is the DnD I know there will be plenty of options. I am not familiar with 5e anyway.
Depends on what you mean by tank.
Clerics can get decent AC, and have OK hit points, mages can use Mage Armor to not have horrible AC but dem d4's really start to hurt after a few levels.
Paladins are, as always, perfectly decent tanks, but that's half casting.
5e did a reasonable job removing 3.x's "Save or Suck" buffet from casters, and getting rid of CODZilla (one of the broken Cleric builds that was PHB only - Better BAB than a fighter, more armor, more HP, plus full cleric spells). You can still super min/max but you are looking for specific spells that target little used and seldom proficient saves which is easily solvable in BG3 - just don't put those spell combos into the game.
5e is intentionally more streamlined - again, it was designed to 'bring back' that AD&D feeling. You can optimize, sure, but min/maxing is difficult because the really broken combos aren't in BG3 (like the machine gun light crossbow fighter).
Right now, use Warlock with the repulsing eldrich blast. Walk backwards every turn. Hit your enemies with a push and kite them forever.
