I’m 19, Male, 5"10, 200 pounds

Those figures sounds terrible in terms of height/weight ratio but it isn’t as terrible as it looks. I’m quite heavily muscled. Very stocky, huge arms, wide chest, huge shoulders and very muscled legs.

A year ago I was 170 pounds with a six pack and due to over indulgence I place masses of weight on and got stout.

My question is I’m now dedicated to losing that weight and I’m shortly going to join a gym and I would like some pointers in how to lose this weight?
What foods should I eat and how often?
How many hours per day/week should I spend in the gym?
What are best things at the gym to use?
What is a realistic target in acheiving this weight loss? I was hoping by christmas but if thats overly optimistic could I have a more accurate time?

Thanks.. any help will be appreciated!!