Find something you like and you are good at, no matter that it is. You will like it because you're good at it and will be good at it because you like it. Doesn't matter how prestigious or cool the job is or if it pays 10 million a year, if you dread going to work each day life will suck.
At 30 you still have your whole life ahead of you. I didn't find my niche until I was 29.
Maybe get online and take some of those "what do you want to be when you grow up" and "what are you good at" tests. Pay for some decent ones, maybe, instead of taking the pop ones on fluff sites. Some people know what they want to do all their lives when they're ten years old and some don't, no shame in being part of the latter.
It might surprise you to see what might interest you, or to look at your real skills without thinking of any particular job. Like, do you love talking to people or can't stand them, like working with your hands, artistic right brain work or rational thought left brain work, those kinds of things. I sure never pictured myself doing what I do, in fact 5 years before I would have sworn it was the last thing I'd ever think about doing, now I love doing it.
Good luck, though. As the saying goes, if you do what you really like you'll never "work" a day in your life.
