So I just started with a new group who all had characters picked out, 2 Barbarians one Dwarf and one Half-Orc, a Gunslinger Teifling I believe, a Bard Half-Elf, a Sorcerer Aasimar (Protector), and a Wizard Variant Teifling.

So I arrive, late, and see we need some kind of Wisom user here, I was told upon arriving most people are new to 5e and this session will be a one off to get everyone accustomed to skill checks, combat and the general feel of our DM's playstyle. Cool. So I pulled out a character idea i've been dying to play. Based on Locke Lamora from the Gentleman Bastard Series of books.

So here I am with a Human Variant Trickery Cleric and a wide party to protect, they're all Critical Role fans and are expecting  A LOT of support to come from the "Support" class. All this long winded intro has been for this, how can I best do this? Besides Bless spam and Healing spells. I mean in a broader sense. I've been my groups DM for 2 years, so being on this side of the board is actually a little intimidating. For the curious I'm level 1, Healer feat and my only "Support" spells atm are Guidance cantrip, Healing Word, Bless, and Sanctuary. Inflict Wounds, Guiding Bolt and my 2 Domain spells round out my list.

To clarify, I got my RP and how my character fits and acts in the world down. It's just the lack of experience of working with a party and having so many to help that is a bit daunting. Any and all advice is appreciated.

Sounds like you've made a great start to me. If you happen to watch any of the new season of Critical Role, Laura plays a Trickery Cleric and might give you some ideas. Bard is also support, so don't feel you can't branch out and try other things. But Guidance and Bless are great early on. Probably lean toward using Guiding Bolt as well; the damage is solid and the advantage on next attack is fab. Use your Trickery power at will to counteract any disadvantage on party member stealth checks, or to give advantage to your party scout.

Cleric Spell slots are a precious resource not to waste. You cant get them back as easily as other full castors. To that end  I think the healer feat is a great way to start. Other feats might help as well like inspiring leader or the always good Lucky. No heavy armor users so stealth shouldn't be an issue as long as the dice play nice. It might also help if you think of yourself less as "support" and more of a "protector".