Step 1: get to level 50. Step 2: do the new season of opulence opening questline to get a full set of 690 weapons and armor. It's blue stuff but you can infuse it. This will boost you to 690 straight away. Step 3: just play the game however you want. There's a butt load of powerful gear sources that'll help you move up to 750. There's pinnacle weapons to grind for. There's exotic quests to do for exotic weapons. There's all kinds of year 2 guns and armor to chase, now with random rolls. You've got dreaming city, forges, gambit, menagerie, raids if that's your thing, etc. etc. After you knock out steps 1 and 2, the world is your oyster. There's so much to do it might seem overwhelming, but just do what you want and play for fun.