A template will not tell you how to do anything - a template is a format that specifies what contents should be included.
There are many threads that discuss the contents and what can be done for Test Cases. You should read these and create what is right for you.
However before you do this most companies have basic templates or at least documents that they have used before - maybe your company has some of these and then you can work to the standards that your own company has put into place.
Hoverer if you really just want a template without doing the work if you search the Internet using the phase "Test Case Template" (like in school spelling does count) there is a high probability that you will find something.
I have not failed. I've just found 10,000 ways that won't work" --Thomas Edison