You can give them a few spells choices, and Cleric spells tend to be more straightforward than Bard spells.Do you really think Life Cleric is simpler than Lore Bard? A Lot of spells to read.
An alternative to valor bard or life cleric is the celestial pact warlock from Xanathars. Warlocks are the simplest mechanically of the spellcasters and the celestial pact gives them healing.
Divine Soul Sorcerer (bard-it-up with charlatan or entertainer background)
To differentiate the two fighters further, make them variant humans and select a feat for each of them.
Hi guys.
I will soon start a campaign with 3 players, full beginners from a TRPG point of view.
So i want to start eeaaasy with the rules and the roll-playing, using pré-gen characters.
From your perspectiv what is the simplest and most effectiv team for 3 players ?
The simplicity aspect is very important : concise sheet, simple combat moove & spells is mandatory.
I'm thinking all humans, Champion Fighter + Thief Rogue + Lore Bard.
What do you think ?
All (non-variant) humans is a no-brainer.
First suggestion: Champion Fighter + Champion Fighter + Favored Soul Sorcerer
In this team, one character can be the tank with high Strength and Constitution: this could be a Champion Fighter with the Defense Fighting Style. I suggest a sword-and-board weapon configuration for even better AC.
The second Champion Fighter still needs to be a decent melee combatant but can focus on a high Dexterity to be better with ranged attacks, and choose the Archery Fighting Style. Make it use light or medium armors without stealth disadvantage, and pick the Criminal background so that it can cover the sniper, sneaker and trapfinder roles at once.
The Favored Soul Sorcerer allows this character to be both the healer (Cure Wounds) and another sniper (Fire Bolt). The downside is that this is not a PHB archetype, it might feel weird for a beginner to start with a non-core character.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.