Affiliate Marketing Secrets

In town there is always are large market and im thinking about opening a stall, (im 16) am i old enough? How do i go about having a stall only at weekends? Is it worth it?
Wheres the best place to buy cheap stock?
I want to earn money and i could work 7 days a week for a few hours on minimum wage but i think itd be a better use of my time to have a market stall, i could have it under an adults name and give them the money if needed.
Basically, rough estimate for a stall (they all look rather shabby tbh and i think theres a niche market to make a stall look a bit more expensive)
A good place to buy super cheap stock from
Pros + Cons etc

I was gonna by ten grand worth of my company stock when it was down to a dollar from it’s usual fifteen or twenty dollars a couple years ago when the stock market was down, and at the last second changed my mind, and then a year and a half later it boomed from a dollar not just back to fifteen or twenty, but to fifty five dollars a share! If I’d put the ten thousand, or even five thousand in I’d be rich, and now I’m kicking myself silly.
but I also realized that our company could have easily declaredbankruptcyy like so many others and I’d have lost all my money, but still it is painful.
Do stock brokers go through this all the time? “Oh man, woulda shoulda coulda” every time a stock goes through the roof but they didn’t buy any.
It’s different for me though, because the ten thousand I wanted to invest anyway, just wasn’t sure where to invest it at the time, and it was my own company stock, and my friends told me to buy it, but for some reason I changed my mind, and my money just sat in my checking account when it could have made me rich.
I feel really bad, since that money would solve everything for me right now in my life, and I was so close. I tried to tell myself that this happens all the time in the stock market, and there’s no way of really knowing what’s gonna happen, but it’s still painful.
Anybody know any secrets to help get me over the guilt?