How can I work at a brokerage firm, or make my own brokerage firm?

No - The brokerage firm that you are working for must give their permission for you to apply for any licenses.
You must obtain a position with a firm that either requires your job to have a license or the firm will sponser so that you can be licensed.

Any degree that is acceptable by a firm will help you with investing. Mostly you should consider majoring in either finance, economis or accounting but you will need courses in statistics and all of the above.

You should start educating yourself before you even get to college or before you finish high school

.Start your education by learning why you should invest and the importance of being able to make your own decisions or how the proâ€™s make theirs.

Here is some reading material that can get you started in the right direction,
What Works on Wall Street by James O'Shaunessey
Beating the Street by Peter Lynch
One Up on Wall Street by Peter Lynch
The Warren Buffett Way by Robert Hagstrom
How to Make Money in Stocksâ€ by William Oâ€™Neil
24 Essential Lessons for Investment Success by William Oâ€™Neil

Get into the habit of making daily visits to some websites like MSN Money and Yahoo Finance. (http://moneycentral.msn.com/home.asp , http://finance.yahoo.com/ . While at MSN following the strategy lab analysts to get a feel for what the pros are doing and why. This site has some basic information for beginners. If any site offers free information, take it.

Other website that can provide instructions and help with procedures and terminology are Investopedia - http://www.investopedia.com/ Stock Charts - http://stockcharts.com/ http://www.investorshub.com/ http://www.1source4stocks.com/, http://www.tradingstocksguide.com/tradinâ€¦

Visit some of the more professional websites like Zacks - http://www.zacks.com/ Smart Money - http://www.smartmoney.com/ Schaefferâ€™s http://www.schaeffersresearch.com/ Some of these web sites will have advertisers who are worth looking into also. And remember, if they offer free information, get it.

Attend all the free seminars you can, just be careful and donâ€™t get pressured into anything you really donâ€™t want or need. Most schools offer courses in finance and economics, but very few will have courses on the mechanics of the investment markets, if they do try taking the course. You may want to consider on-line courses, the New York Institute of Finance use to have such courses. Try to get some fee information from the stocks exchanges they all have (had) free booklets, SIAC and some of the regulators (FINRA SEC MSRB CBOE) may provide some free literature.

You at least have made the right decision to start investing, this is the first big step and it wonâ€™t be your last. Keep taking those steps forward and along the way never take the advice from people that are not in the market or try to tell you not to invest.

Good luck on your journey