1) These days I would start with the Unreal or Unity engines. Most games are programmed in C++, but if you use someone else's engine you might be able to get away with just using whatever scripting or data systems they provide.
2) For a full sized, complicated game (as in not a fairly simple phone or casual game), you are usually talking about years of development time.
3) In theory it is possible if you have programming, design, art, and sound development talents and a lot of time on your hands, but in general it is way easier to find other people to do the parts you're not good at.
Depths of Peril, Kivi's Underworld, Din's Curse, Drox Operative, Zombasite, Din's Legacy, & Drox Operative 2