Accidentally removed Trash-Folder

You did NOT remove the trash, because there is no way you could do so.

To make it easier to follow tbirdvet advice, here is how you quickly reach the file you need to delete:

In Finder, press Command-Shift-G and paste

  ~/Library/Preferences/com.apple.dock.plist

Control-click on this file and choose Move to Trash; then restart, or perhaps easier, type the following line in Terminal

killall Dock

Find the file "com.apple.dock.plist" and move to trash. Then restart your Mac.

An aside to your early issue

To get the replies to your question in chronological order by Date

Click on your User " Hanna Larsson " >> >> " Edit Profile and Preferences "

Scroll way down and look for >> >> " Other Preferences "

Change the >> >> " Default thread sort " to Oldest

See Luis response.