I'm thinking of picking up my old project again. I was working on a Flash based RPG. Walk around using WASD, use mouse to aim, interact, attack and cast spells. It had a decent start, I had enemies spawn, proper animation for walking, working spellcasting and attacking.

I wanted to have it in a web browser, and you can save your progress. The save files would go on the web server. So you can load your progress from anywhere.

Question: What language should I use for coding the game and server communications or whatever. I'm not sure how to make Flash contact a server or anything like that, to load saved information. All it would really have to save/load are variables and booleans.

I'm willing to learn a new language, I pickup quick!!

After some more googling and research, I may just stick with flash.

So, new question: Where are some tutorials, or how can I communicate with server to get information. I'll need to learn how to save/load information for game progress with Flash (Actionscript). Eventually, perhaps, have arenas so it would need fast server.

It depends. You need to give a lot more information than that. Have you written full spec sheets for every single thing you can do? If you haven't actually designed how the game will work, then you shouldn't be trying to make it yet.