Peter and James and the Disciples and others who were "Seeking first the Kingdom of God and HIS Righteousness" were the "Little Flock". At least according to the Jesus "of the Bible".
Zacharias and Simeon and Anna were also of God's "Little Flock". Cornelious also was grafted into God's "Little Flock".
The Sect of the Pharisees "which believed" were trying to place the SAME Yoke on the Necks of the Disciples in Acts 15, that the Pharisees "which didn't believe" had tried to place on the necks of the Disciples and their Jewish Fathers.
Acts 10:
10 Now therefore why tempt ye God, to put a yoke upon the neck of the disciples, which neither our fathers nor we were able to bear?
Peter
directly connected the doctrines and Laws (Yoke, Burden) the Sect of the Pharisees "who believed" were placing on the necks of the Disciples, with the doctrines and Commandments (Yoke, Burden) the Pharisees who "didn't believe", had also placed on the necks of the Disciples and their Jewish Fathers.
My point is that Peter was there when Jesus taught these things.
Matt. 23:
1 Then spake Jesus to the multitude, and to his disciples, 2 Saying, The scribes and the Pharisees sit in Moses' seat: 3 All therefore whatsoever they bid you observe, that observe and do; but do not ye after their works: for they say, and do not.
4 For they (Pharisees, not Moses) bind heavy burdens and grievous to be borne, and lay them on men's shoulders;(Necks) but they themselves will not move them with one of their fingers.
A person who is interested in the Truth of Christ can go to the Christ's Words to find out
what the burdens were that the Pharisees were Laying on the necks of the Disciples and their fathers. Those who do this, and believe the Christ, will understand what the "Yoke" was that the Sect of the Pharisees "that believed" were trying to place on the Necks of the Disciples in Acts 15. (Matt. 15, Mark 7, John 8, etc.)
It seems prudent to point out that in the TRUTH of the Jesus "of the Bible", there are "many" who "believe" Jesus is the Messiah, who prophesy in His Name, who build massive religious businesses in His Name, who even cast out demons in His Name, but because they Transgress God's Commandments by their own religious traditions, (Work Iniquity) Jesus doesn't know them. And therefore, although they believe Jesus is the Christ, they are Not of HIS "Little Flock". The Jesus of the Bible explains this and even warns about it, but "many" who come in His Name, although they believe HE is their Messiah, do not really believe much of what HE says.
Matt. 24:
4 And Jesus answered and said unto them, Take heed that no man deceive you. 5 For many shall come in my name, (Like the Sect of the Pharisees who believed) saying, I (Jesus) am Christ; and "shall deceive" many.
A perfect example of this is the Sect of the Pharisees "which believed", placing the same Yoke of manmade doctrines and religious traditions which cause those who follow them to "Transgress God's commandments", on the necks of men.
But the "Little Flock" of God, turned the Gentile converts "AWAY" from the religious philosophies of the Sect of the Pharisees, "which believed", towards the real Moses, and God's Laws HE was chosen to give to the "Little flock" being Read every Sabbath by those sat in Moses Seat.
From there, they would become learned "Of the Father".
Tit. 2:
11 For the grace of God that bringeth salvation hath appeared "to all men", 12 Teaching us that, denying ungodliness and worldly lusts, we should live soberly, righteously, and godly, in this present world; 13 Looking for that blessed hope, and the glorious appearing of the great God "and" our Saviour Jesus Christ;
So you are Right about believing Jesus, concerning being "Learned of the Father", both Jew and Gentile, how to live righteously, Holy and Godly in this present age. (Matt. 5: 17-19.)
But you are wrong about the Sect of the Pharisees "which believed" in Acts 15, who were tempting God by placing a Yoke of bondage on the necks of the Disciples that their fathers couldn't bear, being God's "Little Flock".
Remember, "A little leaven leavens the whole lump".