I flew in about 2 weeks ago.
LA County requires masks if you're out in public. Wear one, if only to be polite.
The Green Buses are running again, but if you're landing at 1 or 2 it's faster to walk, and 6/7/8 it probably depends on time of day. Also be aware that they've closed off some corridors for whatever reason (maybe reduce exit door staffing). If you land at 6 you can't get to ground transport by taking the escalator down in the hallway between the shops - the doors at the bottom that lead to the curb are closed and marked authorized personnel only.
Not sure about Uber, but Lyft is back to matching drivers and riders instead of the PIN system because volume is so low.
Take pictures because you'll never see LAX that empty again.