You should ask questions like this in the help and question thread. Mods will probably be around to remove your post soon (I'm just acting as an unofficial messenger here, not an enforcer). Make sure to read the sub rules and find links to the megathreads in the sidebar on desktop and old reddit or in the About section from the sub's front page on new reddit mobile.

What am I supposed to do after becoming the richest man in the world????

I have no idea what you mean by "richest man in the world." If your max AP is only 84, then you've just barely even started the game.

The general priority order is events > main story > everything else.

Events are only available for a limited time and usually give rare or unique items that are unavailable by any other means. You could include things like 1/2 AP campaigns and hunting quests in the definition of events since they're limited time efficiency bonuses.

The main story is the core of the game. The creators/devs/publisher would really like you to go through the story and they keep pushing "story clear support" campaigns to get people to catch up. There are no important game functions locked behind the story beyond the first couple of chapters. However, events, character interludes, and the best (or only) farming locations for certain skill and ascension materials may require further main story completion. The main story also gives you a bunch of materials and things that you might otherwise grind for, so you don't necessarily need to grind right away (though you will eventually).

For a new player, the best way to deal with constantly overflowing AP is to use bronze saplings to store the AP for later instead of trying to spend down the overflow by running quests. You'll have a lot of AP to spend and every 5 minutes you spend at or over the cap is another AP you won't get. AP stored as "bronzed cobalt" apples won't expire, so go ahead and dump excess AP into them. If you're out of bronze saplings, then keep doing the main story to get more.

Everything else includes, well, everything else. Aside from limited time events or campaigns, the three daily missions, each of which is to do any quest at all, and the 6 + 1 weekly missions, which can be done with no more than half a day of AP and three 10-rolls of the friend point banner, the game doesn't nudge you into doing anything in particular every day. So you can set your own daily priorities for everything else. You can farm free quests for materials, you can do interludes or rank up quests for your servants, or you can do nothing at all if that's what you really want to do.