If we stay on the premises for one night, can we get an express ticket for each person at the theme park for the next day?

Yeah

What Neil said

If you stay at Loews Portofino Bay Hotel, Hard Rock Hotel® or Loews Royal Pacific Resort you automatically receive Express pass with your booking. Otherwise you can purchase an add on Express pass at the concierge desk in the hotel, or at the park.

Not sure, im confident you'll have to buy them. I dont think its complimentary with your stay.