Create a Group in facebook follow the below steps:
Step 1: Go to your Facebook home page.
Step 2: From the left side menu click on Create Group.
1. Open - anyone can see your group, join your group and search your group.
2. Closed - everyone will able to search the group, ask to join but can't see posts only the members of the group will able to see the posts of the group.
3. Secret- Only members have access to the group.
After you have done with all the steps click on the Create button.