I am in my 30s and still wonder what I really want to do!

It can be easier to start off by identifying what you *don't* want to do.

Think of the jobs you've had and write down what you liked and disliked about each of them, like this:

Restaurant Work
I liked ... fun coworkers, fast paced, time went by quickly, close to home.
I disliked ... nasty customers, time dragging on the register, smelling like food, crappy pay and schedule.

If I had to write that list when I was still at that job, I might have come up with different answers. I know that I like fast paced jobs where time goes by quickly because I've had jobs where the day lasted F O R E V E R.

When I make lists like these, I try to compare and contrast each job. Why was X better than Y? Well, at X I got to spend a lot of time outside of the office. I never knew I enjoyed that until I wound up at Y, where I was locked indoors for 9 hours a day.

I don't think that there is a 'right' choice. You can change your mind later, and probably will after you gain more experience and knowledge about the world and your own preferences. I worked a variety of different jobs before accidentally finding myself with a career in IT. It grew organically. It wasn't something I went after or chose.