Planning your first trip can seem overwhelming but it doesn't have to be. In no time, you'll consider it fun.
You're smart in giving yourself so much time.
Here's what I would do....
1) Decide what type of things you like to see and do. Are you art people, history buffs, scenery lovers...a combination of all or it changes daily?
2) Go to a large library in your area, or a bookstore with places to sit, and look at numerous updated travel guides--not just Ricks. (ETBD is a must as a general resource.)
3) Look at the areas you want to visit and start making lists of things you want to see.
4) Go online. EVery country and major city has a tourism website. They are great resources for information. (No need to wait to visit the local tourist office until you get into town. You can do it online.)
5) Then sit down and decide what things are must sees and what can wait until another trip.
6) Learn about travel times between destinations.
(con't)