Not sure if you already did, but apart from the valuable responses from @asutosh_jena and @Prince_Shivhare you may also want to have a look at the AEM Maven Archetype. It generates all the required project structure for a typical AEM project.
When it comes to SCM (e. g. GIT), you need to add the whole project folder to your GIT repository. In order to collaborate with your team members, you will need some kind of remote repository where all your work comes together (e. g. GitHub,BitBucket or something similar; there probably already is something similar within your organization).
If you are a customer of Adobe Managed Services (AMS) or AEM as a Cloud Service (AEMaCS), you may also refer to Adobes Cloud Manager that comes with a remote GIT repository. However, that GIT repository is commonly setup to be a mirror of another GIT repository at the customer side and may not be feasible as your central GIT remote server.