A most pratical question: How can I "call" - what does it mean to seek his presence / HIS guidance - to humble myself before G-d as the prophets teach us again and again? What does HE expect from me? When will HE answer my prayers / cries / humiliation?

Humiliation is not a good thing- not humiliation of yourself, not of others. Be a good person; keep the commandments incumbent upon you (if you are Jewish- the 613 commandments of the Torah. If you are not Jewish, keep the seven Noachide commandments that, as the Torah teaches, G-d commanded you at the time of Adam and Noah). Try to make the world a better place as a result of your existence in it.