When you pass the mouse over the text, you will see a frame around it. This is the frame where the text, title, or photo is located. In the corner you see a pencil icon.
When you click on this icon you will see on your left hand a section where you can edit the tekst or image. Don't forget to click on the green update button to save the changes.
For both editing image and text you use this process. The only diffrence is with photo you choose the option choose image. While on the contrary when wanting to edit an text you rewrite the text. Don't forget to use the update button to save the changes made.
The clock with an arrow is to undo the changes. The second icon is to see how it looks on different devices including phone, tablets and computer. Third icon is to have a preview of the changes.