The mandolin and fiddle have the same fingerboard, thus the notes are in the same places. The chart below show you what those note names are. Remember some notes have two names (G# and Ab are the same note, one above G and one below A).
If you want to study more music theory, check out my Easy Music Theory for Fiddle and Mandolin book and check out the video series "Music Theory Fiddle Mandolin Violin"
If you want to study more music theory, check out my Easy Music Theory for Fiddle and Mandolin book and check out the video series "Music Theory Fiddle Mandolin Violin"