The main squares on the front page are ‘POSTS’ so If you want to create a new square on the front page then create a new post.
and of course you can edit the ‘POSTS’ by going to posts and finding the post you want to update.
Follow the pictures in order :

 

Then remember to update your post.

 

Try that and If you understand I’ll send you one about Tables.

 

Let me know howe you get on 🙂