How do I start being a responsible grownup with my finances?

I am irresponsible. I’m bad at paying my bills on time and I leave dishes in the sink for days and I’m always late to stuff.

Someday I am going to be old and I will still probably be irresponsible. But I don’t want to end up old and destitute and pathetic and a burden on society, so I realize I need to start saving money while I’m still relatively young.

Where do I start? Should I open an IRA? Roth or traditional? Or do I buy mutual funds? Or index funds? Or something else entirely?

Also I have no idea how one actually does any of the things I just mentioned. I hate my bank (Bank of America) and would rather they have nothing to do with my long-term savings and I assume there are other companies that manage this kind of thing. But I am also not rich and not trying to invest huge sums of money, so maybe those companies aren’t appropriate for what I want to do?

I would love to hear about how other people have successfully created a financial safety net for themselves, especially if you started out young and dumb and irresponsible like me. Whatever advice you have is helpful.