Injunctions

Questions:

How do I get an injunction against my ex partner and how much does it cost?
Someone has put a video/photograph of me on the internet/ is showing video footage of me in a compromising position to friends etc, without my permission, what can I do?
Will the police get an injunction for me?

What do I do first when I arrive at court to give evidence as a witness?

For police non-emergencies dial 101