What should you do? Whatever it is that you like in the game. A set of Neo-ishgardian gear will be enough to get you through the story content of the next patch(dec). You would be slightly behind the "average" player, but no where near enough to hinder your ability to do the story. If you want upgrades now you have a few options. You can buy an item in Kholusia that will add 10 levels to your crafted gear(you lose the ability to overmeld in the exchange). You can also spend allegory tomes(these have a weekly cap, so if this is something that interests you try to cap each week until the patch) for pieces at that same 490 level. The current alliance raid will also drop a different set of 490 gear(these have a 1 piece per week limit right now - visible armor slots only), along with a token you can use to upgrade some of those allegory pieces to level 500. And if you like more challenging encounters, the current extreme trial(seat of sacrifice) will drop a weapon upgrade for you and you can try to get into the savage raids which have a full set of gear for the taking. Mind you, when the next patch hits a new tier of gear will be released(gear upgrades come every even numbered patch, and this next one is 5.4). You could potentially just wait 4-6 weeks, then start getting the level 510-530 gear that the rest of us will also be working on. This will be new tome gear(with new tomes), new crafted gear, new extreme trial weapons, new raid gear, and new savage raid gear.

Aside from gear, you could work on side story quests. The eden and nier raid lines both have story associated with them, as does the optional trial storyline(the weapons). Eden and the trials being continued in the next patch(nier is the following patch) means catching them up now will give you more to do right away next patchday. As was mentioned previously, the relic is tied to the Bozja story that you could get into. The previous expansions also had optional raids and trials, each with their own storyline(none of these are relevant gear wise, but you can find glamours minis mounts and music you may want) - and each one also had their own version of a relic quest(awesome glamours, kinda grindy). If you want a change of pace from combat, you could get involved in rebuilding Ishgard via crafting and gathering(we're rebuilding the Firmament section of the city via the ishgardian restoration quests and content). The beast tribes would fall into this "change of pace" by my estimation(even the combat tribes dont need much fighting from you), and again each has a story to tell. The Hildibrand and Postmoogle side quests are more comedy oriented if you could use a couple laughs after some downer storylines. You could get an apartment to decorate(or try for a house, though i can say from personal experience Lamia isnt the best server to try to find a house on). You can spend time in the Gold Saucer racing chocobos and playing cards(they have some nice glamours/mounts/etc you can save up for). You can dip a toe into PvP(not this games strong suit, but some enjoy it). You can level other classes. You can obsess over fashion. Or work on your mount/minion/music collections. Or recruit the perfect squadron. Or try to get all the rewards from the current limited time events(yokai and make it rain) before they end. Or challenge yourself to complete Palace of the Dead/Heaven on High solo. Or unlock all the optional dungeons you might have skipped and run each of them once to see what they have to offer. Or try to get into a good static group(in general FF14 savage raids are completable in a PuG setting, but a fixed group tends to make them much easier as you can develop your own strategies and learn to work with each other) to prog the next savage raid tier with.

Ultimately, there are a lot of paths open to you but only you know which ones you would enjoy walking.