Step 1: Go to Media Tab
Click on Media under Side-menu
Then click on the Upload Button.
Step 2: Upload Box
In the Upload box, click on Browse which will directly open you to your local storage, select an image/video from it or you can also drag a file and put it in the space provided.
Click on Upload.
A private option is available if you want to upload media publicly or not.
Your image or video will be successfully added to your Media collection.