Hi!
The best way indeed is to use the PHP shortcode (template function), here is a small documentation chapter on it: https://goo.gl/8NlmBq
Unfortunately I cannot make a step-by-step guide on it, as each and every theme has a different code structure, so there is no exact method that works for all of them. I believe you IT team will definitely know how to place it 🙂
Another possibility is to use the search as a menu item: https://goo.gl/RxJZf3