I want to become a formula 3 driver?

I'm 15 have a strong karting background and I'm looking to take the next step into racing. I was looking at the skip barber racing school for there 3 day racing school but I was wondering if there's any other programs that I could do that are better and my mom and dad said if the price isn't insane I can go over to Europe and join a racing school over there. I'm just looking for anyone who has experience in the racing industry and how to get into the best programs at a young age. I been racing

I race in go carts right now powered by a Honda GX 270 4-stroke engines and they can get up to about 40 mph even though that doesn't seem like a lot the place were I race its a narrow track with sharp turns everywhere so there's no need to go 50 or 60 mph

A "strong karting background"? What does this mean? Are you a State or National Champion? How many years? How are you in the wet and dry? You're 15 - you should already be a champion in karts and looking at moving on to Formula Ford.

The "best programs" - as in, programs like Red Bull Junior Team and McLaren Junior Team - pick up ten or eleven year olds out of karts. They don't tend to pick up 15 year olds who haven't even raced a formula car yet. Gosh, at your age, Mitch Evans was the Australian Formula Ford champion and preparing to race F3 in Australia so he could get ready to go to England.

And racing costs money. A LOT of money. The budget for Formula 3 would be $1million+ PER YEAR. No sponsor is going to touch you if you haven't got a ton of results to back it up.

To be a F3 driver you need to live in Europe permanently. Start by racing Formula Fords, Formula 4, or something similar and work your way up.
http://www.britishformulaford.co.uk/