Peak watts means surge at start up, not sustained running. Figure out what you intend to run in the house and their load, and size generator accordingly.
If you intend to fuel with other than gas, understand available watts will be less as propane is less efficient than gas. Natural gas even less than propane. So size accordingly. Bigger is always better.
Get a soft start on your ac unit regardless, but definitely so if you want it to run on a portable.
Understand where it will be and Understand what it takes to get fuel to it, electricity to the box, and exhaust away. Moving it to set up in a storm and in the dark sucks.
My portable is in the back of the detached garage near the breaker box. Through wall exhaust, natural gas flex line stays connected, but valve turned off.
Research and understand break in and maintenance needs. Dedicated fuel and oil funnels as well as replacing the stupid bolt for the oil drain with a quick valve makes regular oil changes much easier.