There are many wonderful hotels and Airbnb/VRBOs in downtown Long Beach, as well as the surrounding area. The venue is also near a metro stop, so feel free to stay anywhere in the city!
That said- we're recommending two hotels across the street from one another as a central location:
The Courtyard Marriott Long Beach
500 E 1st St, Long Beach, CA 90802
or
Best Western Plus Hotel at the Convention Center
517 E 1st St, Long Beach, CA 90802
There are fancy-shamancy or more budget friendly options within a few blocks if you want a different hotel that's nearby.
You've got your pick of airports! LAX, Long Beach Airport, and John Wayne airport are all close to hotels and the venue, fly into whichever is most convenient for you.
The LA Metro has a stop in Long Beach, which connects to the whole city. It's a long trip, but you can use it to get to many of the popular spots in Los Angeles. Plan your trip at https://www.metro.net/
There is also a bus and several independent shuttle services from Long Beach to Disneyland