You should always OPEN a midi file if it is a complete song composed by someone else. Otherwise you loose important data.
Use ATL A to select all, drag the song ( tracks) to where you want them..Zoom in and use snap to 1/8 note. Never start at zero. MIDI needs a few ticks to get going. It's OK to put the count in at the first 1/4 note of measure one. But never have a note on absolute zero.