If you want to ride Flight of Passage without a long wait, I’d get there 60-75 minutes before rope drop as the others said: they typically start letting people in to Pandora 30-40 minutes before scheduled park opening. If you just arrive at scheduled park opening, the wait will already be well above 90 minutes, if not a few hours.
I wrote a post about our day in August - our walk in and time to ride on that day was longer than most people report since, but the idea of how it works might be useful to you:
By all accounts, if you get there early, rope drop FoP and then go on Navi River right after, you can have both done by 15-20 minutes after scheduled park opening.
I wish the touring plan estimates would stop telling people the waits are low first thing in the morning, or at least mention that people are getting there very early.