In terms of healing, Omega is right. To go even further, the sub-classes offer further healing options. Life Cleric packs a punch when it comes to healing. You could even go Lore Bard and choose healing spells for your bonus spells (Aura of Vitality being a great one). If Larian is incorporating Feats, you could add the Healer feat for even more healing power.
As for the Tank debate, I would argue that, while there is no traditional tank in the MMO sense, there is some tanking to be had.
- A Totem Barbarian built to grapple can hold down one or two opponents and absorb soooo much damage.
- The Protection Fighting Style available to Fighters is a way to incentivize an opponent to attack you instead of an ally.
- The Battle Master Fighter can use their maneuvers to either shut an enemy down (trip attack) or incentivize them to attack you (goading attack).
- The Sentinel Feat prevents opponents from moving away from you to attack others.
- Paladins have Compel Duel to lock an opponent into attacking only them.
- Conquest Paladins (if we are pulling from outside of the Player's Handbook) have an aura that can literally keep enemies from moving if they're frightened.
- Some spells keep the opponent from moving, thus ensuring only you are attacked. Booming Blade comes to mind.
So there is a lot of options for "Tanking," but there is no Taunt button you can press to automatically pull enemies to you.
