How many accounts can I activate as home at one time?

if you take it then it should automatically be activated for a month. in your account page in the top right of the xbox home screen you can see how much time you have to make sure it activated.

You can only set 1 console as your Home at a time.

on this 1 console is there a limit to how many accounts can set that console as a home xbox for game share?

How many different accounts have your console set as their home console? There is a limit to how many can have set to one console.

When your account is logged in, are the other accounts on it able to access your games?

It will work just by recovering the account on said console.

Be aware tho you are limited on how many times you can switch home consoles.

How many accounts are you using? because you will need two accounts the main one and secondary account. The main one you will need to set one console as the home Xbox then sign in with sign out with the main account and sign in with the secondary account
then on the other console sign in with the main account.

Xbox #1

Main Account: (Set as home Xbox) and signed out (do not remove from console)

Secondary account: singed in

Xbox #2

Main Account: Singed in

Secondary account: not necessary

You can switch your home console 5 times a year if you have used all 5 I can tell you how to reset them if necessary.