Unfortunately, you have not provided anything that we can use to help you solve this issue.
Alfresco is two different web applications. One is alfresco.war and the other is share.war. The most common problem in this situation is that the share.war successfully started but the alfresco.war did not. This could be for any number of reasons.
So, after double-checking that you are using the correct credentials, check your log file, which is $ALFRESCO_HOME/tomcat/logs/catalina.out or $ALFRESCO_HOME/alfresco.log and see if it holds any clues.