My take:
Most people lose before they even start. The main reasons: totally undercapitalized, totally naive about market and absolutely no business plan.
Look through a franchise magazine sometime and see how much CASH capital is required to be awarded a franchise. They then require you to go through a fairly extensive training program and they monitor you with financial software to assure your success.
The failure rate of established franchises is quite low.
IMHO, the basic requirements: $25,000 trading capital, Direct Access Screen, US resident, stocks only!!! And read some basic books, such as Bill O'Neill's, even if you don't follow his methods, he does explain how and why certain stocks move up or down. Basic technical understanding but keep it simple.
I always believe that a proper stop loss should be a function of the amount of your cash account. 2% of a $50,000 account is $1000. That is the maximum I would want to lose on any one trade. Or use 1% if you are going for small moves.
SteveD