We travel quite a bit and I would second going on a tour. Especially for your first time and if you are traveling outside of the country. There are lots of travel forums you can join to pick up tidbits on how to get the best deal, the best places to go and so on. Another idea is to check out your Junior College. Some offer travel packages after completing so many units of a language- like Spain!! It is a big world out there. Have fun and enjoy it!
P.S. Before paying for an all inclusive, like the many they have in Mexico, keep in mind how many times you will realistically eat at the hotel. For some it is a great deal because their idea of a vacation is to go to a resort, enjoy all the admenities, and never leave it. For us we like to get out more. Again, in Mexico in the Riviera there are many places to see and places to eat that fit well into a budget. You just have to be wise about what you pick to eat. Stay away from soups and stews where they use water. Only order drinks from a bottle and never with ice !!