>>49365
Go to your city hall first, as you should be eligible to receive funds from some national and European organisations. Check your local cultural centre to see it they don't already have a department in charge of those things.

Go to each and every business of your city, ask for the boss, tell said boss you need a sponsor for your cultural event. Show him the file you prepared in advance about what will happen in this event with as much details as possible. Prepare several copies you can leave them.
Be prepared to arrange spots to promote the participating businesses.

Prepare a means to cash-in their "participation". You should decide on a recommended sum to donate in advance.
You can arrange a specific bank account beforehand or any other means. Get some receipts ready (because they can and will declare it in their tax form as it gives a right to deduce them from their taxes).

List alternative means to help the event. If a company owns a lorry you could use to bring the stands and the infrastructures, for example, while schools or other sports clubs (if applicable) could become your free workforce.

You could sell goodies door to door to get some extra funds (check in your city hall what you need to do for it to be legal).
You can try to make an account on websites like gofundme.

Hope this helped.

>>49365
Contact the people behind Attack on Titan.