Ah man you'll be grand.
Letterkenny is a grand spot - plenty of pubs and nightclubs all v close together so you can choose a different one every night if you want. Lots of pubs have bands playing or you can head to the nightclubs for a DJ or a dance off with a stranger! In saying that there are plenty of people starting fights and messing outside of the clubs but i suppose your gonna get that in most student towns.
Lots of shopping all around the town....Tesco, pennies, dunnes, tk max, argos, lidl, aldi x2, heatons, easons, boots ....
It has all the usual amenities too like bowling, cinema, and a massive sports centre just outside the town. The college also has a great gym/sports hall on site. Loads of GAA, soccer and basketballs teams to train with or join so plenty to keep you busy. LK has a decent golf course too if you fancy it and they have good student membership offers.
I am not from the town, I live about 40mins away but credit where credit is due they have built it up to a decent town indeed. I'd say it would be a great place to go to college