How long are you planning to be there? When do you plan to go?
There are four different APs, seasonal, power, preferred, and premier.
There are 2-park APs and 3-park APs.
If you get day tickets (like a 3-park day ticket) and use the entitlement to enter Volcano Bay, then you can only update to a 3-park AP.
Seasonal is the cheapest but has blockout dates; make sure
There is Florida Resident pricing for APs and non-Florida resident pricing. Make sure you pick the rest one to compare to price of day tickets.
Non-FL Resident AP prices (don't include tax):
https://www.universalorlando.com/web/en/us/tickets-packages/annual-passes/promo
You only need one AP (any type) to get the AP rate at the hotel, but you have to specifically book an AP rate (they are limited). Staying on property gets you access to unlimited express pass (room key card that is scanned at the express pass entrance for the attraction).
Since you're staying on property, you don't need to worry about the ones that include parking. But blackout dates apply so make sure you check those before purchasing the AP.
