Congratulations on pursuing a new career. Real Estate can be very rewarding, but is very challenging too. There are a few steps to consider. First, getting a license can be done without choosing a company. There are independent schools you can do in person or on line to complete the necessary courses to become licensed.
Little of what you learn in licensing will make you successful. The day to day work is not what they focus on. You need to know these things, but you're education is just beginning.
Once licensed, you'll need to have a brokerage to work for before you can start. All agents must be supervised by a managing broker and they are responsible for your continued training and will suffer from any mistakes you make. This is the biggest decision you'll make.
Finding the right fit for you personally as well as for your continued training is critical. Most new agents are out of the business in 2 years or less, so the odds are against you. Meet with several companies and learn what they have to offer the new agent. Some will not be interested and almost only accept established agents and others will be prepared to put you into a system and hope you come out the other end successful. Expect to pay a lot of money for your continued training and necessary supplies. This is a 100% commission field and you only get paid when/if you are successful. It could easily be weeks or months to get that first check, so have some money set aside to work from and pay for the start up costs.
Part time is difficult. Clients can be demanding and want to get their questions answered quickly and be able to see homes on short notice. Some do work with modest success part time, but I suspect one job or the other suffers.
I hope this gets you off to a good start.