WHO really is the faithful and discreet slave?
The the context of parable in Luke and Matthew make clear that the question is rhetorical and intended for self reflection. The writers used the slave story to say that all Christians should behave as the "faithful slave' did in dutifully serving their master. There is nothing in the texts that suggests a prophecy of eclesiastical authority.
How is Gods people being feed?
'God's people' is a cultic lable. From a theist's perspective surely all people are 'God's people'. It is only in exclusivist cult circles that a small body of like believers condemn and maligne all others as Satan's people, unbelievers, worldly etc. If these assume such a title as "god's people' it would then seem strange to ask how they are fed. Surely God would be feeding them.
Where is jesus Christian Congregation that was started by him?
The NT does not even hint that Jesus started any congregation. If we assume that the writers meant their readers to believe he did then the answer is simple. The congregation that was started by him have been dead for 2000 years.
Where should I go to worship God and be taught by him?
You are assuming that there is a God that needs to have a human representation to be his mouth and ears. And that this representative apparently looks so much like everyone else that a person has to discover him. This belief makes easy victims of cults. There are a great many cults and cultlike religions that claim to be such a mouth for God eager to meet them.