I'm a lapsed piano accordionist who now plays various flavours of concertina and melodeon but I'd offer the same advice as for any free reed keyboard instrument -- get the hands working together as soon as you can.

If yours has a stradella bass (I think most Bayans do) with bass and counter-bass buttons, on PA I found practising left hand scales under right-hand chords helpful for getting the geography of the bass buttons into my subconscious.