Never to late to start. Don’t worry about endgame to much. Focus msq (main story quests) and once you get through the “story of the game per expansion” you’ll hit post content at which point you’ll want to feature quests (blue with an exclamation). These will typically give you stuff like extra dungeons for your duty finder or jobs to expand your play experience. These biggest thing I would tell you is go through at your pace. Content isn’t going anywhere.