I need help with a game I am currently playing. The game file is attached. Please take a look at it and tell me what you would do if you were playing this game. I am not going to set any specific parameters. That way, everyone with various play styles can give me advice on how they would approach this particular game. But I won't make secret of the fact that I am preparing to conquer my enemy to my north. However, I am completely open to any advice that involves delaying war to the distant future, and building up my civilization first.

Any advice will be highly appreciated!!!!!!!

You don't have bronze so war anytime soon is out of the question. It's a duel map, and he has all the religion and his capital's on a hill.
Build up your cities. Usually this means granaries first, barracks come before useful units. Improve tiles. A spare unit can explore the edges to look for seafood. Get slavery.
3 tech paths to military victory:
1) ironworking. You can try to overwhelm him axes/swords(granary barracks, farms/hills, whip liberally, chop everything).
2) horsebackriding. granary barracks stables, expand and connect horses/silver, mass horse archers, some suicide flanking 2 to weaken combat 2 or combat 1 shock, easy win.
3) catapults. set slider to 0, build library, run 2 scientists, then tech construction. build granary barracks archers*. Research construction, build/whip/chop catapults.