Hi anon, getting into flying is easier than you think, it's quite structured once you get started. I'm assuming you're asking about being a commercial pilot in the UK/Europe? Before jumping in, you can usually take a demo lesson at a flight school. It might be worth asking and going for a flight, just to see if you really like it or not. If you like it, you could even start building hours or learning ground theory tomorrow. Anyway, here's how to get into flying..
It might sound self-explanatory, but start with a flight school! As with uni, you'll want to do some research before you enrol, flying is expensive and you want somewhere that's good value (read: not always the cheapest), safe (you'll be flying, you want well-maintained aircraft), and with a good reputation. Once you have your licence schools can help hook you up with interviews (how I got my job) so you'll want to go somewhere with a good reputation and with plenty or "airline partners," it pays off in the long run. Pay schools a visit and ask as many questions as you want, be sure to talk to current students as well (and graduates, if you can get hold of anyone, PM me if you want) and see how they feel about the place.
Course wise, there are two big ways of doing it: Integrated or Modular. The difference is that, as the name suggests, modular training can be taken bit by bit, which can be useful if you need time to fund your training or have family you want to return to often. It also tends to be cheaper overall. Integrated is faster and airlines have slightly lower entry requirements for graduates of these courses, which can help. It's tough but as long as you keep up with the material you'll be fine. Airlines know it's tough and they respect that.
Finance is usually the most difficult. There's no student finance available as there is with uni, the best you'll be offered is a loan, so you'll also want to think about your cash situation while you look at schools. You'll also want to stockpile a few thousand ££s for after your training: most airlines require you to pay for a type rating, and if you're offered a job, you'll want to take it quickly instead of spending time negotiating with banks. Some flight schools offer loans as well through parter banks, so be sure to ask when you visit.
All the best at uni, use it to your advantage when you do interviews, but don't expect schools to be very interested in the details of your major. Airlines are interested in your licence, not your degree, so it essentially serves as a backup plan and perhaps for some additional knowledge. I went straight to flight school and nobody has asked me about university.
In terms of licensing, your flight school will either take care of it or explain what needs to be sent where. At the end of whatever course you take, you'll want a commercial pilot's licence, multi-engine instrument rating, and a multi-crew cooperation course certificate. That allows you to fly commercially. Don't worry too much about this yet, all in good time.
Lastly, get a Class 1 Medical! You can do this tomorrow if you want, most schools require you to have one before you start anyway and it can be a good way of flagging up any potential issues before it's too late.
Best of luck and happy holidays! Sorry for the long reply, reply or PM me if you want more details.