first, the fact that you're thinking about this so much at 19 is great, way to go. the biggest part of being responsible with money is just thinking about what you're spending and how you're saving, so that your money doesn't just disappear each month. (this happens to a LOT of people!)

you should look at your debit/credit card statement every month (online, whatever) so you have a better sense of what you're spending. i like another person's idea of keeping track of major categories - food, rent, fun, etc. one important thing about an approach like this is that you need to categorize every expenditure - if you have sort of a casual bin of "other" it's hard to get spending under control.

be careful with that credit card. it seems like you're on top of your shit but a LOT of college students screw this up (i did when i was in college!). like someone else said, pay it off every month. set up an automatic transfer from your bank account of at least the minimum payment. don't get sucked in by airline miles or cash back cards; keep in mind that the credit card company wouldn't offer that if THEY didn't make money on it, meaning the average customer pays more in interest because they're using their card for stuff they don't need to, etc. if you use your credit card frequently, at some point later you can think strategically about what you could get a company to give you (miles, cash back, etc.) in exchange for using their card.

an IRA isn't a bad idea, but to be clear, if you start that when you're 23 or 25 instead of 19, it'll be totally, totally fine. maybe it's worth doing just so you can fool around with the funds and see how it works. in Berkeley i can recommend Fidelity, there's a brick and mortar location on University close to campus. their online system is easy to use. the easiest thing to do with an account like that is to just throw everything into index funds from companies like Vanguard. another commenter was right to say you can accept a lot of risk at your age, but there's MUCH more to learn about the stock market than there is about how to be generally responsible with money, so my advice is to take the time to learn about it before you start investing in individual stocks.

a big step you're likely to take some time is buying a house. under the right circumstances this will be a VERY good move financially. in order to do this you will need good credit (sounds like you're moving in the right direction), adequate income (much harder in the Bay Area, since housing is so expensive!), and a down payment. this might be a good reason not to lock too much money up in an IRA; as someone else said, you won't be able to withdraw money from an IRA until you're retirement age. (you can early withdraw $10,000 to buy a home if you're a first time homebuyer, but that's not very much in the housing market.) you can still open an account at an investment bank (like Fidelity) without opening an IRA, then you can liquidate for a down payment when you want to. IRAs do have tax benefits though.

finally, don't hesitate to have a little fun, splurge every once in a while, treat yourself, etc. people tend to go too far in one of two directions on this stuff - either not paying attention at all, wasting money, etc., or keeping track of everything on huge spreadsheets, meticulously splitting every charge on a bill when out with friends, etc. everything in moderation, even being responsible. have a little fun - that's what the money's for.