Fist of all you will probably still be a child until you graduate college. 22 is the new 18.

That being said... Debt.. learn about it and do your best to avoid it.

Rejection... practice getting rejected... the more you practice getting rejected when it doesn't matter the the easier it gets when it does. Ask girls out and get rejected, ask more girls out, repeat until there are no more girls left to ask out.

Its OK to have a casual thing unattractive people. Once the lights go out it feels just as good sometimes better. Its easier to learn your own kinks if you don't worry about what your partner thinks of you. Your friends will judge you, but who cares they probably are to busy judging and not getting any. Once you point that out they will shut up.

Social skills are learned like other skills, through practice, taking risks and putting yourself out there. Its not easy to get better at it and sometimes you have to treat going out and being social like you treat a job, go out and make it happen every day you can. Even when its scary, new, and you have to go out alone.

When looking for a job nobody gives a f what you actually learned in college or what your specialty was. People are more impressed by internships, portfolios and projects. Spend more time and effort working on this and have something that you can say is yours. Grades don't really matter, just gotta pass.