1. Open Teams. Click the Teams icon on the left hand side then the "+" button towards the top. Click "Create Team".
2. Fill out the Team information for the Team you are wanting to create. Once you click create, the Next page will prompt you to add users.
3. You will now see your newly create team site. From here you can share posts with each other, Files, and Notes.
When you create a Teams site, it creates an adjacent SharePoint site. While in the site, click the 3 dots towards the top then select "Open in SharePoint".