Step1: For a new forum topic you first need to join any group that you like. Click on group at the top menu
Step2: Click on any group where you want to create a new topic and join that group.
Step3: Click on Forum and you will find the option Create New Topic….
Step4: Enter the topic title.
Step5: Click on the button (Text) and write a description of your topic in the body.
Step6: Add a picture and submit the topic.