I keep crying because I'm scared to grow up, what happens if I don't get into a good college what happens if I get a bad job, what happens if I don't find true love what happens if I have no one by my side...

What happens if you go online and ask a question and no one answers?

Part of the reality we live with is that life IS about chances. We only know how it begins and how its going. No one can tell you your ultimate future. That part is yet to be written by you. In time you will find someone when the time is right. In time you will decide what your goals are and how to make yourself happy. What you can look forward to is the wisdom your going to acquire as you age. It helps with your chances of attaining your goals. Keep your head straight. You have the power to create your future. Empower yourself with positive energy. Start every day with a blank canvas and make yourself a masterpiece.

There is no bad school ( accredited) there are those rated higher, but in general, unless you want some specific positions, it does not really matter, Most people are not going to Harvard, so your local state university will work very fine for almost any carrier you want.

Jobs, you will most likely work several jobs you don't like, the issue is being happy, It is much better to work a job you like, and not work merely for a higher paying job.

I could easily make 3 times what I do now, if I wanted, but I am doing a job I like.

But often in life, jobs come and jobs go, you find a happy personal life and a job merely pays bills to allow you to live a personal life.

I have never known a old man who says, he wished he had more time to work, they always regret not having more time for family.

And next date, meet people and go out, seldom is the people you date though high school the people you marry latter ( sometimes but seldom) And life happens without a marriage partner, learning to be happy with who you are.

I'm worried about YOU worrying about these things when you are only 12.
My suggestion (without knowing much about you are what is making you sad and scared) is to find a best friend. Everyone needs one. You find one by being nice to someone you know and like, and asking to do things together, and complimenting her, and sharing your innermost feelings with her.