if i buy a form whit you do i need to have my own host or you givme one?

If you mean just subscribing to Jotform, all your form data will be hosted on the Jotform server. You can access it when you login to your Jotform account.

However, if you mean buying the Jotform platform, you have to find a host that meets the Jotform app requirements. http://interlogy.com/products/jotform/

Thanks!