While I have no idea what your template is designed to do, in principle what you need is to protect your document with a password. You will find Protect Document on the Developer tab as well as on the Review tab; use either. after clicking on Restrict Editing, second from the top is "Allow only this type of editing," with various choices, including "Read only" and "Filling in forms". Select the approrpiate choice for your needs and click on Start Protection, below. You will be prompted for a password. DON'T LOSE IT!!

Does that solve your problem?