Hi @Sammie Yang!
Congrats on deciding to get licensed in February, that's exciting! It is a career that can be very rewarding, but takes a lot of hard work.
It sounds cheesy, but start with your own personal purpose to getting licensed. Then, I would spend some time looking to 2017 and setting some goals for yourself professionally. The first of which would be to get licensed, and get your license hung at a brokerage. If you haven't started interviewing brokers yet, I would do that first while working on your license. Ask them all the question you posed here. You will get varying answers from place to place. Some teams/brokers provide leads to their agents in some fashion, others do not.
No buyer, seller or investor is frankly going to wait for you to be licensed, if they are truly motivated to act. It's great you are thinking of how to attract and generate business, but don't put the cart before the horse.
There are hundreds of ways to generate business. I think it's best to first know your purpose and set your goals - then to build your daily goals around those things along with your strengths. Some people love going and knocking on doors in neighborhoods - not at all my thing, but hey, it takes all kinds. Others enjoy paying for internet leads from one of the thousands of sources in doing so from Facebook ads to Zillow.
For your personal sphere, I would not recommend reaching out to people you know well, or haven't connected to in a while, and asking them for business. It's a quick way out of a friendship. Sadly, it's what a lot of brokerages preach as their main business model. Just find a way to re-connect, be a friend, see if you can add value somewhere in their life, etc. Don't do it for the purpose of generating business, do it because you care about this person, and you want to live a life of giving and adding value.
I'm no 20 year vet myself, and don't by any stretch have all the answers. For every person, the path is going to be different.
If you ever want to reach out, I'm always happy to chat and see if I can help in any way. Just send me a DM! Best of luck getting started!