Hi Saskia. I am sure that someone will help you with this soon, but in the meantime we need a lot more information about what you have done so far. eg:

I assume you have a Domain Name and hosting for your site arranged? Your webhosting company should have given you the information and password you need to upload your site. Do you have this?

Are you using the built in uploading system, or an external one?

Have you given the servers enough time to update and display your site? The first upload can take a while before everything displays.

Let us know and we can help further.