Server can be in «Activation in progress» status from 15 minutes to 3 hours. After this server gets «Active» status and is ready to work.
Also, you may have server in «Ordered» status. It means that you haven't paid for this server yet. Make sure that you have enough money on the account balance and add funds if not. Then server gets «Activation in progress» status.
If server is still in «Activation in progress» status after 3 hours, get in touch with us via chat or ticket from Control Panel.