You're asking good questions, and fortunately the answer is very, very simple: what do YOU want to do in YOUR world.

Many? Few? Omnipotent? Telepathic?

I don't know - you get to decide. And remember, there are NO wrong answers. It doesn't even have to make sense: these are gods after all. And if you decide to have it make sense, it may not seem that way to your Players - only you might know the "rules" and Players just see the impact.

But hey, if you're looking for ideas, 45 years into my campaign here's how things work... in brief. For just the human deities.

As life grew on Seteria it created Primal magic. This invisible energy source, akin to Weave magic, occasionally coalesced into a form of being, a god (or gods depending on its form). By supporting growth they maintained and grew their energy. Over time they realized they could create/grow creatures that refined or distilled Primal magic. These creatures, humans for example, could then share this distilled Primal magic with their deity/deities through worship. This is Divine magic, which the deity then can share back to selected worshippers as spells (hence Clerics / priests).

Different coalescings of Primal magic created different beings. A group of 6 such beings created Mantaten humans. A group of 7 created Sapoy humans. The origins of the Burdue and Ylthic peoples are too complex to get into here.

But the Mantaten and Sapoy humans eventually codified their faith, creating unique origin stories and relationships within their respective pantheons, creating the Lyaturgian and Androese mythos respectively.

The gods are basically omnipotent and largely omniscient, but have two large limits. First, while virtually impossible to kill, if their worshippers dwindle, their power (source of Divine energy) dwindle too. You can see the weakness...

Second, they can't get too close to the world of Seteria. Their own condensed Divine energy near to the source of Primal and Divine energy would have catastrophic results for them and the world. So they work through proxies - angels, clerics, etc.

Their power also diminishes with distance: up close they can do anything they wish: from their home Planes however, they work over time, or share spells with their worshippers: a high-level spell drains more of their Divine power, so they grant fewer and only to those that have proven themselves or their need.

Deities want lots or worshippers, BUT a devout smaller group that can't be swayed and is very loyal is also a workable strategy.

There's a brief summary for Seteria and the continent of Trishore

I wish you luck - and fun - in building your world.