Career
I would have told my younger self that finance is a viable career path. My family always told me it was a disgusting career but I have been drawn to it since I was a teenager. With the modicum of accidental success I had in the confluence of software and finance, I feel like I missed out on an enjoyable career. Don't listen to your family, who probably are like crabs in a bucket anyway, follow your own path.
Investing
I would also tell my younger self that being young is NOT the time to be reckless with investment. Compounding is hardest early on, so I would actually put 80% of savings into things that compound at 6-7% (say SPY or REIT-like things).
The difference compounding $25K at 6% for 40 years vs $50K over 20 years is a cool 2 million dollars. And if you can't save $25K a year as an educated person, then you might as well go on welfare.
The rest, I'd send over to my friend Asadullah in securities...
Side hustle
Get a side hustle, no matter what. This helps you do two things: 1) release the energy you are unable to release at work, 2) a secondary possible income stream
Career + Investing + Side hustle
The bottom line is this: get a high paying career, save as much as possible early on and invest conservatively when you're young. An optional side hustle can accelerate your financial independence.
You may also want to plan/expect to be fired at 40 years old if you have a normal job. That's what I tell my kids. Then not being fired or "made redundant" is a bonus.
Edit: More notes
Financial freedom is an amazing feeling. By following a path to financial freedom, you give yourself the opportunity to become REALLY rich.
Say you start saving $25K/year from the time you're 20 and you get "fired" at 40. You now have no residual income but a nest egg of about $1 million. With compounding at 6%, let's say you start drawing down $25K. That changes your return to about 4%. That still continues to compound.
The point is that it isn't about getting rich but about ensuring that in the event that you get fucked, you can live with dignity.
The best part is if you don't get fucked, the above strategy also makes you rich.
I followed this, purely out of a survival instinct, not due to any specific education or help otherwise, and was able to put aside enough from 20-30 resulting in a nest egg of about $450K at the time I first got onto this website. Continuing that, and protecting it from divorce lawyers (please don't ask me to write a book), has resulted in a nest egg of much bigger than that. Now I am in a position where I can say fuck corporate life.
Without a divorce, and had I followed my desired career path, I can conservatively say I'd have 2-4x what I have now but honestly, I'm still pretty happy with where I am.