im 23 myself, and i have gone through a great transformation through the years, i started off as a scrawny geek, too clever for my own good, got frustrated with "society" and became a "freak", getting into fights and violent tantrums, then as i came out of adolescence i calmed down, stopped being violent, and gradually opened up to people. leaving school and getting to know "the real world", together with a few years in the army (compulsory in my country) have taught me alot. heres my 2 cents, all in my very humble opinion:
i think wanting people to like you is a catch 22 situation. if you care so much about what others think, i imagine youll tend to try and change around them, and "give them what they want". its boring to be around people who have no opinions of their own and who always agree with you, the more you try to be liked, the less you will be liked. "be yourself" is actually very good advice. because you will never achieve 100% likeability. its best to be true to your own convictions. that way your conversations with people will be heart felt, and you can keep them going for longer, as everything is coming from within, and not from what you think the other person wants to hear - which you have no way of knowing anyway.
i think accepting that sometimes people wont like you is important. it will happen no matter what you do and you have no control over it. imo, once you embrace this, and free yourself of this concern, aknowledging that sometimes theres just nothing you can do can be very calming and even empowering.
infact, the very moment i decided that i dont want ANYONE to like me, is the same moment that people started to like me! and once i calmed down about it and stopped being belligerent, i found myself surrounded by more and more people, some of them were types i never thought i could get along with. these days im friendly with the same kind of people i used to get into fights with at school.
think about the people you like yourself. i know id rather be around people with strong convictions and opinions, people who can surprise you, people who speak from the heart and dont mess about beating around the bush. if i annoy people (except for when i do it on purpose) then what the hell, you cant win them all! just like some people get on my nerves, i will also get on other peoples nerves - thats just how it is.
it all boils down (imo) to not caring. if your true to yourself, and disassociate yourself from thoughts of what others want, friends and popularity will inadvertently build themselves around you, so long as you stay yourself.
i for example, believe in complete honesty, not because of religion or anything of the sort, just because i see no logical reason to lie. if ever i dont feel like talking about something, ill say that i dont want to talk about it, instead of inventing a lie. i also like "shock value", and tend to point out uncomfortable truths in those awkward moments you know everyone is thinking it - im that guy who points it out out-loud and makes a joke of it. for this reason, people know they can always count on me for an honest opinion. even my mother, if shes trying to decide what to wear for a family get together, shell come to ask my opinion - not my fathers : p. i make fun of myself very often, its a sign of self confidence and people will respect you for it. if something bothers me - i point it out, if i like something - i point it out. i believe that if you express your opinions, you draw others to yourself.
your shy and reserved? embrace it, thats who you are.
authority? i think authority respects its own kind. this is one of the places i think being completely honest - even if you may get into trouble, comes in handy. why was i in the executive office at 3 oclock in the morning during a night shift? i went to get a bottle of coca cola... my boss was so shocked that i told him upfront and didnt invent something up - he laughed and went on to regular work conversation without even telling me "dont do it again".
reading over all ive written, its a bit fragmented, im sorry, sometimes i find it hard to express myself. i hope i come off as humble, and i hope i was of some use. best of luck