The domain name will be active at the moment the payment is processed and the invoice must be paid for a domain to be activated.
Do I have to wait until the expiration date to renew it?
No, it is not necessary and you may renew at any time.
How may I change the Registrant of a domain?
The change of Registrant of a domain is a Domain Name Transfer for which you must follow a process that begins with the Domain Name Transfer Form and corresponding documents.