I have a question or two.... >.>

Why am I "co-DM"? :P

What level are we starting at?

How many characters can we have?

How are we generating characters (standard array, point buy, roll)? 
Can we use DnD Beyond to generate our characters? (As a note, if you create a campaign in DnD Beyond, then I can join it and share content so everyone has access to everything, but you're still the DM and I can't see anything as far as notes go.)
Additionally, how do you want our characters to know each other, or otherwise come together in the first place? Are we just going to do the standard hook?
Any additional equipment you'll allow us to start with? Do we have to take starting equipment, or can we roll for gold?
How much background do you want for our characters, and would you use any of a background in the game?
Do we care about alignment and PBIFs? (personality, bond, ideal, flaw)

Is anything banned? i.e. races (eberron/ravnica), items, classes, multi-classing, backgrounds, feats, etc.

I don't know how any of this works, but if this thread is set as "full", then how would we invite people?

What alternative rules are we allowing? (flanking, drink potion as bonus action, gritty realism, etc.)

How much do we want to RP in general? Are we just going to be murder-hobos?

I may or may not have further questions... ;)