>>5963495
It kinda sounds dumb but you really gotta live the life and certainty will come. There were a lot of people who were in disbelief and just by going to church ones realized they are finally home, Fr. Seraphim Rose is a very famous case in which the only thing that really gave him certainty and a complete trust in the Lord was going to church just once. Once you've come and you decide to live an orthodox life your spiritual father (or at least the parish priest) will guide you towards the next steps.