Replying to T2i astrophotography help

so i just got in from trying to do my first astrophotography and all i can say is should it be that hard to get a pic in focus? i am definitely not seeing a Infinity logo on my 18-55mm do i need an expensive lense to get this...i see an infinity symbol sure helps out with in focus night pics. All i was trying all night to do was move my focus ring little by little and i never got it completely right:( although I'm glad i figured out how to see the stars etc. with high iso and low f stops it kind of got me mad nothings that in focus tips?