New to Joplin. I imported several notebooks from Evernote (exported as .enex; imported as markdown). Went very smoothly but in several of the notebooks, at the top of the note list (sorted by date created) there are notes what have a small checkbox next to them. What do these boxes indicate? I hesitate to check them since I don't know what they mean. One of the notebooks has over 2500 notes and has seven such notes.
If it looks like the tick box in the picture below it means the note has been imported as a "to-do". If you want to change it to a "Note", right-click and select "Switch between note and to-do type".
If you keep it as a "to-do", ticking the box will mark it as "complete".
Where "to-dos" appear in your note list and whether they are visible after being completed is controlled in the "View" menu.