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