To change or delete an entry, scroll to the bottom of your diary dashboard, under my diary entries, you will see all the ones you have made, next to the entry in question you will find edit and delete buttons. You can choose who can read your diary on your diary dashboard.
When writing the diary you can choose (top left) ‘Draft’ as publish status. After writing the diary and clicking ‘save’ the entry will show in your entry list and by clicking the title you can see how it looks.
You can then click on the ‘x’ to publish it.