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.
