Hey Scotty I seen with your used sports car videos young drivers drive the heck out of them and abuse them. I am 20 years old and looking for some legend like this what should I do despite with my insurance premiums and the fact I get good marks in college meaning grades.
Can you realistically afford one?
Ok. Im gonna address your question at face value; and assume that you can put together the budget and find one for sale.
First thing is slow down; you’re not ready. A lot of first time super car owners don’t know what they’re getting into or how to drive it. You don’t want to wrap Godzilla around a tree the first time it rains. So I’d start by finding a GTR club and couple of forums and learn about how the car drives. Go for a ride along. Maybe even take a driving class.
Then (and I’m not being facetious) get a 370z. Learn how Nissan Engineers do things and how to do your own maintenance. Then when you’re completely comfortable with it, start looking for your dream car.
Anyway, there’s a lot more to say. And this is really a repair and maintenance forum. But I think you get the idea.
Neither
If you want a sports car get a 5 l Mustang don't buy a supercar unless you can pay for it out of pocket cash up front
I am 20 years old and looking for some legend like this
Are you sure you’re ready for Godzilla?

what should I do
Civic Si.
Trying to work hard on it with myself and the help of my parents
Get something that you can afford yourself, you shouldn't be asking your parents to help buy you a car, especially not a flashy car like that. Odds are you wont really respect it/ appreciate it. And in the car community, most people don't like when a young guy or girl is mommy/daddy funded. I saw it in college when I was 20.
P.S. Working hard isn't something you try to do, you just do it.