If you try to start your server and nothing appears to happen, first ensure you have entered your MP3 name and key under settings > auto dj tab.
MP3 name and key is required if you plan to stream in mp3 format, or you can stream in aac+ format without a name and key

MP3 name and key must come from SHOUTcast and be exactly the same as the name you placed your order with and the key must be exactly the same that you got from SHOUTcast, use copy/paste

There are several other reasons for problems starting servers, many times the reason will be included in the error message, you should review the entire message and correct any problems noted