Hi - the test case format and content varies from company to company. Please check inside your company as what format is being used ,because after you write them you may need to rework again to suit what your company / project wants.
You may also search in the forum under the search option as this has been discussed before.
Next time kindly create a new request if you have a new query as this time you have added to exsisting one
For someone new to testing it is impressive that you landed a QA Lead position. Unless your company is just starting a formal testing program (which I doubt based on your employer) than there should be some templates already in use within your organization.
There are already thousands of posts in these forums so it is easy to find existing answers to basic questions. I suggest you familiarize yourself with the search functions available for this site.