I'd probably just shoot my younger self. It's not suicide when it's murder. Or something. Anyway obliterating the universe with a paradox would definitely be a better result than the hell we're currently living in.
One thing I'm learning from these types of questions is that knowledge isn't power, money is. There is precious little I could do with future knolewedge outside of personal/family matters without first using that knowledge to make as much money as possible.
First I wouldn't buy my Mustang, I'd rebuild my Jeep and stick to Offroading instead of racecars wayyy cheaper over time. Then I wouldnt get out of the Army because the real world sucks, from there everything I know now wouldn't have happened and I probably wouldn't even live in the State I live in now
I'd rather take two more hours to collect some data from the stock markets, and how they went up and down after our beloved lunatic CEO's bigmouth accidents.
If my previous consciousness coexisted: Support my young shitbrain self in the tough times he's going through and become the best supporter anyone could ever want...or maybe that already happened and that's why I'm constantly being sidetracked.