Sort:  

No worries, will take some time to get used to it. You can click the 3 dots next to you message to edit. I think if you just delete all and save it will go away.

There is also a great guide to Hive here https://jryze.me/hive/ from @ryzeonline that the good people in the Hive Discord recently made me awhere off.

It's complicated with hive. On Ecency and on Peakd you can delete posts. ecency.com and peakd.com. You can log in there with your hive account, find the post you want to delete, or edit, and get on with it. That's one way to make it work. There must be more ways.
Here you can read about it, how complicated it is: https://ecency.com/hive-189306/@ryzeonline/hive-a-complete-beginners-guide-with-fun-doodles-pt-1

Just realized it is the same as the link I posted. Looks like this is part 1. Maybe the one on his site is more complete?

It sure looks the same. Your link looks better though, but the length would antagonize me. My link is only part 1.

Don't sweat it, you will get the hanf of it ;)