Thank you for your question.
In order to file a suit, you would need to serve the defendant(s) with a "complaint", or the petition against them. Unfortunately, however, because every case obviously has different facts and circumstances, there is no boilerplate document or template. Each complaint is drafted by the plaintiff bringing suit.
I did try to find something to at least give you a little guidance as to typical format, ythey way the case is laid out, etc., and the closest I came was this complaint
from a case in Texas. You'll see it references "defamation
" - slander is the spoken form of defamation of character.
If you live near a law school, you can check with their law library - the law librarian on duty should be able to point you to some pleading form books that may have basic bare bones outlines for drafting a legal complaint. If you don't live near a law school, you my want to check with your local courthouse as well - I've been in a couple that have a law library for parties to do research in, and they have always been staffed by a law librarian for persons needing some assistance.
I realize this isn't ideal, but that is because there is no general template. There is no doubt that it is going to take some research and work to draft the lawsuit yourself.