you're getting a lot of US-centric advice here, don't let that distract you
save and invest no matter how small
live within your means...you're a student so that should be the norm...take those habits with you when you start earning
dublin no matter what anyone says (particularly people in property who are flying high right now) is a very small town
at the end of the day, don't forget that.
try to get a summer job lined up with any investment bank in london for next summer if you can.....you'll learn way more than you will in dub. get the names of temping agencies and be persistent........these people are looking for people who can knock out menial office tasks in these places...it's a great way to start....google robert walters, they are a big temping agency...
if you'd rather stay in dub then hammer your contacts and faculty people to try to get into a summer placement (even if it's the mailroom...it's a beachhead from which to advance)....BoI or AIB but also merrill have a big office there..be bold phone and persist..you'll get something......who knows, you might be able to keep the job (and the cash) part time when you go back in second year......
with uni....it's very important as they say to have fun and suck the life out of it !! but take care of business first so you have even more time for fun.......work effectively, be organised, don't let your time be wasted.....learn to speed read your prescribed texts ahead of time, makes the lectures more valuable per unit time spent......

there's always an angle for smart people !
(Another thing: there is a post here somewhere by a guy who goes by the moniker "I trade 4 money"....man, read that one, don't be like him...see what people are saying to him and try to see why he's going to take a fall...he's 24 )
Here it is
http://www.elitetrader.com/vb/showthread.php?s=&threadid=78466&perpage=6&pagenumber=1
Read it and understand , ask questions if you don't understand......and btw, well done for coming on here to get advice....road is long, way is narrow.