So we are going to level 11 and I want to be a eloquence bard, how would I build it and have him not attack at all and just be support?

My eloquence bard hit level 10 before the campaign ended. Mostly her role was to buff and debuff with some utility abilities to support the group.

There are many options but what got the most mileage out of me was Cure Wounds, Detect Thoughts, Mirror Image, Bestow Curse, Slow, Counterspell, Dimension Door, Silvery Barbs, and Wall of Force.

I also had Dissonant Whispers as an attack that would also create space when I was inevitably targeted. Synaptic Static also is a good debuff spell, though I didn't get to use it so much because of a lack of grouped enemies in my campaign. Vicious Mockery is another debuff that I recommend even if you do not wish to do damage. The damage is terrible and it's real value is in the debuff. Suggestion and Geas were also in my list, though I had never used them because I never needed to as an eloquence bard with a minimum 23 persuasion/deception.

Mage Hand, Minor Illusion, and Prestidigitation fill out your remaining cantrips.

Unsettling Words will carry you far. The only wasted use of this is the one you don't use. I forgot about Comprehend Languages to complement Universal Speech. I only used it once but since we had no wizard, it was better to have it than not have it.

Expertise for me was on Deception, Insight, Perception, and Persuasion. Max out your charisma, with whatever left going to dex and con. I took the Charlatan - Baldur’s Gate background because it had everything I needed, but you will find your own that works for you. A good jumping off point though. Studded leather armor is a must, a shield if you can manage it, and a one-handed instrument as your focus.

I took the Observant feat so I could watch conversations across the room and inform my party of conversations I was not in. I took Lucky as well, for obvious reasons.