Most flights to Ireland from the US are the overnight variety. If this is your first trip to Ireland then it's better to get acclimated and shake off the Jet Lag then attempt a long drive your first day. Unless you fly first class and can get a really good night's sleep.
It's not too late to to start planning. Have fun it's an adventure!
Theresa, I think it might be wise for you to pick up a guide book or two, and have a browse through the questions on the top right hand side to get an idea of things you'd like to do.
One person's dream trip could be another's nightmare, so read up a bit on what there is to do here in Ireland, the different regions and sights etc and what you'd be interested in. Then people can give you more advice.