To delete one of your posts on Mastodon, go to the post, click ⋯ then select "Delete".
To edit a post, click ⋯ and then "Edit". Editing is usually better for corrections as it means links, shares and replies carry on working.
"Delete & Re-Draft" is a relic from the days before post editing was available. It deletes the post and puts a copy of it into the post creation box. You probably don't need this, but it's useful for changing post visibilities.
In the official app notifications are visible by clicking the bell 🔔 icon at the bottom of screen. Make sure you've clicked "everything" at the top if you want to see every notification.
Once you view the notifications in "everything" mode, it will mark them as read and the dot will disappear.
You can't clear notifications on the official app, but if you log in via your server's website (https://mastodon.art) there is a "clear notifications" option at the top of notifications.
@FediTips "Delete & Re-Draft" is what I use for posts that have a mistake within 5 minutes and before someone interacts with it. Don't underestimate how easily other kinds of servers (not Mastodon) fail to grasp the BASIC EDITING and leave your post with ages old errors that you managed to edit even right away.
Yeah, I hope they keep the feature, it definitely has its place.
Think the alt text editing bug has been fixed now though?
p.s. Another case is if you accidentally include sensitive information in a post, and want to remove it. Editing doesn't do this well enough because the previous versions are still visible if you click on an edited post's "edited" link.