Hi @Chew_Thiam_Soon ,
Yes, even with Community Edition, you will be able to integrate with GitHub and perform branch analysis, but you will only be able to analyze your main branch and no pull request decoration. Please see here for more info: GitHub Integration | SonarQube Docs
Also, in your sonar.properties file within $SONARQUBE_HOME/conf/ folder, there are properties you can set for your internal proxy. You might need this if you need to access Marketplace to download plugins (see “Update Center” in sonar.properties file) for example. If your internal network can access GitHub, then SonarQube can connect to GitHub and it should work.