Changing market

[Account Closed]

Hello BiggerPockets!

Due to the extremely small percentage of responses I've gotten on my previous posts I'll try to ask briefly. 

I have a dream of moving to the states, in my case California. I still want to be an investor engaged in real estate, both commercial real estate and residential, such as fix-n-flips and other things. I'm only seventeen years old, but already plunging my way through books about real estate as well as podcasts and other sources of information - our greatest commodity. 

I'm not completely sure when, since I'm taking my high-school diploma in 2017, and I'm planning to become a millionaire much earlier than 30. I've tried and succeeded with mapping out parts of my investing plan, but major parts are still left.

How do I choose what niche is most interesting, before even trying them all? Is the answer to try them all first? And in that case, is it more conventional to try them all here in Sweden before moving to Cali?

Secondly, how do I tie connections as effective and fast as possible when new, with no family or friends in California? Don't say it's not possible - because it's not. It's just very unconventional, but definitely attainable. What are your advice?

Lastly, how do I know when I would need an investment company, to hire my own contractor, sales person, the one for raising capital and the one that is responsible for acquisition? 

Thank you guys for taking your time to read and answer my concerncs, I really appreciate it. Hope I can help you in return in any way!