First and foremost DO and DELIVER.
If you find something that would interest you, than search for a way to try it out. Set a goal in that field and commit to it with your whole heart. Even if it is a small goal.
Don't quit. Even if you find out that the task is not right for you. There will always be unpleasant tasks in your life, the sooner you get used to doing them, the easier your life will get. After you delivered you might look out for the next task in the same field or in a different one, this is up to you.
This gives you confidence (you can do anything) and it builds your character. Through these experiences you will learn what you like to do, what you hate to do, which are your strengths and weaknesses. And by delivering you will build good rapport with people.
One of my biggest challenges was, when I was working for a student organization. I had to call companies and find internships for students from foreign countries. I had two goals: find a great experience for a random person, overcome my shyness. At that time it seemed as a hard job for me, but with every call it got easier. In time I learned to start and steer conversations and did help a few people to have the time of their lives who became my friends. I learned also that I'm not a sales person, but I need the skills to get where I want to go in life.
On top of that the knowledge, that I can overcome my fear to speak to strangers is one of the best motivation I have in my life.
I would like to disagree with you, that you are running out of time. I know people who started to look for what they like in their 30's and 40's. You are currently in the best time for this, but it is never to late to start.
And last but not least. Read, go to seminars, listen to podcasts and talk to people you look up to. Find your role models. There are a lot of people who went through similar situations and you can learn a lot from their experiences. The people and things you surround yourself with can make a huge difference on your behavior. So choose them consciously.
The next book on my wishlist is for example - So Good They Can't Ignore You by Cal Newport.
For financial advice look for the books by Robert Kiyosaki i.e "Rich Dad, Poor Dad" or "Cashflow Quadrant"
Don't think too much about your salary yet, you want to know what you want first. But it is a good though exercise to think about how you could make money from the things you do.
Have a great journey,