Build based solely on what is in EA or confirmed for release right now if it had multi-classing. The focus here would be on conversation, observation, and thief skills and support capabilities. Note that there are better choices for the order and selection of skills if they fix the Lore bard for full release.
Level 1
Lightfoot Halfling
Rogue 1
Entertainer
Str 8
Dex 16
Con 11
Int 12
Wis 12
Cha 16
Skills:
Race - Stealth
Background - Acrobatics and Performance
Class: Deception, Insight (expertise), Perception (expertise), Persuasion
Level 2
Bard 1
Skill: Investigation
Spells:
Cantrips: Friends and Minor Illusion
Lvl 1 spells: Healing Word, Heroism, Sleep, Dissonant Whispers (the most in character damage spell if you really need it)
Level 3
Bard 2
Spells: Charm if you want to go all in on the talking, Thunderwave if you feel like doing some damage while knocking opponents away from you.
Level 4
Lore Bard 3
New skills: Arcana, Slight of Hand (expertise), Intimidation (and add expertise to whichever talking skill you like most)
Spells: Invisibility, and swap Heroism for Enhance Ability
Level 5
Lore bard 4
Feat: Resilient - Constitution (this will help you survive better
Spells: Hold Person (non-damage spell that keeps a bad guy from attacking)
Level 6
Rogue 2
nothing to pick here
Level 7
Arcane Trickster Rogue 3
Cantrips: Mage Hand, and at this point you are out of decent non-damage cantrip choices. I would go with Shocking Grasp since it helps you run away from badguys and Chill Touch to stop them from healing. They have the best 'support' type secondary abilities
Spells: Color Spray, Disguise Self, Find Familiar (so you can have a little bird friend like the one who guided them to the keyhole in the mountain)
Level 8
Rogue 4
Charisma +2 to make your talking skills better
After that, I would go back to bard to get more and higher level spells.
I hope this helps
