Your first time doing taxes, go to the public library and grab the paper copy of the instructions, even if you're submitting it electronically. Read them and highlight anything that's confusing or important.
Laundry: Use less detergent than you think, and colder water than you think. Don't machine-dry any wool and most synthetic fabrics.
ADHD? Look into a bullet journal for keeping track of important info. This is not a product, it's a method, and you can do it with a 50¢ composition book. The main benefit for someone with ADHD is that it's stupid easy to start and doesn't break if you forget to do it for a day or a week or a month.
Buying insurance? Hiring a contractor? Know your budget and get at least three quotes before deciding.
You don't get promoted by being good at your current job. You get promoted by asking for it, or by jumping to a different company.
Start investing now. Pick a stock or fund that's boring but steady and buy $50 worth (or more, if you can afford it), rain or shine. Don't stress about optimizing it; even boring investments should have a return well above inflation.
Never lend anyone money. It will destroy your relationship 90% of the time. If someone needs help and you want to help them, just give them the money. Either they'll pay it back some other way or they'll pay it forward, but no matter what it won't be hanging between you.
If times are hard, don't be afraid or ashamed to take advantage of programs or food banks. That's what they're there for. You're not taking it away from someone who needs it more, most food banks have a big overflow from week to week. If you feel bad about using these programs when you're down, well, make sure to donate or volunteer when you're up.
Worst of both worlds, they're the suburbs of underwear.