First time generator/homeowner question.

Hey All - noob here, trying to figure out what size generator I need and any recommendations. Recently moved into a house with an existing L14-30 outlet outside and a wired generator panel in the basement. What's the max size portable generator I should get to use the available capacity? I am thinking dual fuel option would be great to have. I think the max wattage is 2500? (See pic). Appreciate any help! Please let me know if more info is needed.