Welcome to the Seas, and kudos on grinding it out to Pirate Legend! Adventures on the Seas are what you make of them, the important thing is to have fun.
My biggest tip is to always keep in mind that this is a session based game, so if you find yourself in any situations where you aren't having fun don't worry about losing loot or anything, you can always Scuttle (to stay on the same server but get out of the situation you're in) or hop to another server and get back to having fun.
There is a lot of freedom on the Seas to have fun the way you like. Sometimes this will come into conflict with other players approaches - just don't stress it and move on to new horizons and adventures.
If you haven't had a chance to yet while you were grinding out some Trading Companies, you might want to check out the Tall Tales - in particular if you like lore and story. These are big story driven voyages that you can take on and run through a narrative. You might also like Adventures - these are newer and are time limited, but keep the narrative of the Seas moving forward. Feel free to check them out and participate.
If you're into having a little out of game action with your Adventures there is also the current Mystery underway (a murder mystery about figuring out who killed a prominent NPC). You could also start diving into that and working with the community to drive that narrative forward. Sometimes things can be found in game, sometimes on social media. There is a thread around here all about the current one.
If you like to tackle more random objectives there are loads of Commendations to chase after and complete. You can find these in the Reputation Menus, each Faction has some and the Bilge Rats in particular have a boat load of them to try out. This can give you something random to try out while you sail the Seas. And of course there is also Achievement hunting as well. There is a pretty good list of those you can review and try to crack out.
But, again, the main idea is to make sure you're having fun out there regardless of what you're trying to do. I wish you the best in all of your piratical endeavors!