I am traveling from Granada, Spain to Barcelona, Spain via Spainair for a flight that is departing at 11:10. I'm not sure how early I should be at the airport for this flight. Also, do the train stations in Spain (Seville, Granada, Barcelona, & Madrid) accept credit cards for train tickets and reservations?
An hour ahead of time should be sufficient for your flight. Granada's airport is pretty small. As for your train tickets, you won't have any problems with an American credit card. However, you can save a ton of money, and avoid standing in long lines at the ticket windows, if you buy them in advance at the Spanish national rail website, www.renfe.com
Even two weeks before I leave?
Sure, why not.....see what's available.