Hi i have some problems for the free domain redirection when i put fre domain i put the domain i want and i have all the index.html and all the things but when i put my url yourdomain.com example don't do nothing so waht i need to do?

You have to buy the domain from an external registrar, such as Go Daddy, Optinom, etc.
What it means by "free" is that it's free to add your existing domain to your Web site, so that when people go to the domain URL, they will see your Zymic Web site.
However, applying a domain that you have not purchased will not work.

oh i don't know thta jeje i meed money my borhtday is coming and my father want to give my hosting and domain ^^

Well, if your father will pay for it as a birthday gift, you should consider some paid hosting.
Nothing wrong with free hosts, and Zymic is one of the best...when it works.
But paid hosts usually have more features and the like, so it's mostly best to go with a paid host if you have the option.
Good luck getting your domain.