Auto part sales.
I used to strip car parts of abandoned vehicles and sell them to a mechanic.
There are a lot of things that I did wrong but I was just a kid. It taught me a lot about haggling, knowing where your power comes from in negotiation, and not being intimidated into bad deals.

I feel get a sense of business early on is very important
Not only to success but to overall confidence.

My daughters spent their 4th-5thgrade summer offering to do 1 days gardening for whatever the person felt was fair at the end of the day. They earned $1500 over the summer. While most of it went to amusement park trips, etc, they intentionally saved $250.
I have a 50/50 deal with my kids that anything they can save half the money for I will match because theyve shown its something that is significant to them in someway. Well they had a whole plan drawn up
They took the $500 and followed what they had seen me do when they were little ones and started looking for thrift store, garage sale, and fleamarket finds. I mostly dealt with medical equipment, electronics, and used books. They took all of my tools and just used them for apparel.
8 years later, They make around $35k a year selling a mix of thrift store finds, and custom pieces they sew themselves. They graduate high school next week, and this summer we should be finalizing their deal with a job shop to produce their first complete line. They pay most of their general expenses. Its pretty rare they ask me for money....they usually ask for financial advice not donations.

So im going to close with a few things Ive tried to teach my girls

Dont be afraid to fail, only Be afraid to fail to try. Plans are the delusions fools suffer as life has its way with them.
Always Be Adaptive.....complacency and comfort breed failure.
So dont sit still....you cant stumble into greatness without moving.
But at the end of the day success or failure is often determined by luck and timing as much as it is planning and effort.
when it goes right, when it goes wrong, when it goes sideways......always seek the value of what works, the value of knowing what doesnt, and really know where the strengths and weakness are for the next foray. Because fail or succeed tomorrows going to be another fight unless you chose to crawl into an hourly grave and mortgage your life away day at a time for an existence that is sure to never make you more money than you need to need to return and keep working. And for some people thats the best way to live.
Id rather spend my whole life failing and trying new things than to just settle in and decay. But Im only 40...maybe my tune will change in another 10 years.