There's no generic template and due to various local regulation it would be difficult to have one master template, but generally sweepstake terms should include, but not limit to:
Campaign overview; What it is about in short.
What is the prize? How many prizes?
How to enter the sweepstake?
Who can participate? Eligibility.
Campaign time frames?
How and when winner(s) is selected?
How winner(s) will be notified about the prize?
How to claim the prize? Prize delivery details if applicable.
Who is campaign organizer?
Limitation of liability.
Liaise with your local legal department in order to create the document and include all relevant details.