if l didn't book the view time，can l enter in the getty center？ Can l wait for entering

They require a reservation

It depends on how book they are. I've gotten them twice. I haven't had a reservation

Unless they have an unusually high traffic day, they still let you in even though it says online that you need one.

Yes you can. Just carry a photo ID and vaccination proof.

I didn't have reservation yes you can go in just need a ID and proof of vaccination

Sometime they're forgot and not asking your reservation.

Yes

Yep