I agree that starting an rts as one of your first projects is going to need a lot of problem solving. Your going to need pathfinding, formations, scattering, AI, multiplayer (which is a huge pain), and many, many other things. It took me five years to figure out that sometimes (not always) its better to work on fun quirky games, rather giant monster games, since I never listen to that "Start small, make something boring" crap.
However, if your set on making strategy games, I will offer one piece of advice.
Think about making an RTT (wikipedia it) a Real Time Tactical game. Like the battles in total war, or empire at war, or knights of honor or many others.
Its only a battle, it can be done (if you design it well) without pathfinding, too much complex ai and has many less systems to make. You can tie the different battles together in anyway you want (a map is normal, but you could use a story, a card game or even I once tried a sidescroller). It lets you make simple ai and units and combat and movement, and then because these are simplier you then get to have fun making cool stuff, or making better ai and adding pathfinding but after you made the simple game so it allows you to learn before taking on the big guys.
Two misc things: 1: Dont add online multiplayer 'till you have made a single player game and feel up for it. Its a hard thing to do and can very much spell doom for a project because it needs to be done before everything else. Try making a lan game if you want, those are much more easy and they let you learn how to design a game for multiplayer, both code and design-wise.
2: Make you map filled with stuff, but not things that need pathfinding. shallow rivers, ditchs instead of walls, high grass, forest, even passable scattered standing rocks can be done, with the right glide code. I made a tank game with all sorts of crud, but I made code for the tanks crashing through it, and going slower and getting stuck sometimes, but for your first project, dont tackle pathfinding or multiplayer, these are things that you get sucked in to, and say "But I need them" and for a early project, you dont. I make my units ignore_models in their move in most of my projects, and just make a few bits of code that cause them to scatter and not stack on each other, it really helps in crowd pathfinding, and the game is still fun.
Have a good time game designing,
work hard.
thegamedesigner.
beware the sock! - 