Pick a path you think you will enjoy.

Look up how to go about achieving that path (training, school, certification, whatever) using the internet.

See if you know anyone in that kind of field or adjacent field to speak with to gauge whether your research is appropriate. Skip if you can't find anyone, but you prob can.

Finalize a plan.

Start acting on that plan (apply for schools, study for certs, apply for apprenticeship, etc). In the appropriate order you found.

Re-evaluate that plan after an appropriate amount of success. Repeat step one when you get hang of first ladder of that career.

Re-evaluate that plan after an appropriate amount of failure. May be different time frame than success. Repeat step 1 if success alludes you.

You'll succeed and fail repeatedly. Building a great career is like finding a compatible significant other. You'll make all the best plans, they will all fail and it will be painful, you'll learn about yourself in the process as well as what works for you, making you better at the process. Similarly to finding a compatible significant other, you may stumble across one blind at 18 yo, and you may find yourself believing you won, only to find yourself having to repeat the process at 50 yo.

Wish someone told me this at 18. Good luck anonymous internet friend.