Getting really formal instruction from an Orthodox spiritual father on advanced spiritual practices outside of the context of the Church is going to be very difficult, if not impossible. I can point you to a few books that explain Orthodox spirituality like Metropolitan Kallistos Ware's The Orthodox Way, and a few primary sources like St. John Climacus's Ladder of Divine Ascent, or the anonymous Way of a Pilgrim that get deeper into this kind of thing, but that's about all I could do.
Now, there are some things in Orthodox spiritual practice that you could do, like practicing the virtues; keeping a prayer rule; fasting; reading and meditating on Scripture; reading and studying the lives of the Saints and the writings of the Fathers; singing Psalms, akathists and canons; almsgiving; etc, etc. that any Christian can do, and even I could help you with that. But as far as things like hesychasm, that's a different ball game.