as @tucknoloji seggested find some one from the same community. I agree its hard to get in touch at first place but once you become part of a community the real fun starts.
We could have help you if you were in Lahore but for Islamabad you can contact @d3vil he and his group is pretty active in Islamabad.
My advice to you would be, start from a small trip. Like Murree, Nathiyagali etc. You can manage it yourself even. Get familiars with mountains in urban area then target for far. You will learn a lot of things.
Directly hitting a long trip for your first time is not recommended.
Best of luck