The Catholics have Guarding Angels sent to protect and watch over people my question is, do they exist in scripture( I know angels exist like Michael & Gabriel but assigning to individuals at birth?!?
Catholicism stretches a Biblical truth to suit their angel-veneration (worship).
Yes, the idea of guardian 'angels' for an individual / peoples exists in scripture. However, while angels are sent to minister to mankind in general, that they might accept the Gospel, a "guarding" angel is granted upon the reception of faith in Christ Jesus, to minister to the newly 'born again'.
Psa_34:7
The angel of the LORD encampeth round about them that fear him, and
delivereth them.
As for instance. Jesus is the "example" (1 Pet. 2:21) for mankind, and had such protection:
Psa_91:11 For
he shall give his angels charge over thee, to keep thee in all thy ways.
Luk_4:10 For it is written,
He shall give his angels charge over thee, to keep thee:
Mat_4:11 Then the devil leaveth him, and, behold,
angels came and ministered unto him.
Mar_1:13 And he was there in the wilderness forty days, tempted of Satan; and was with the wild beasts; and
the angels ministered unto him.
Luk_22:43 And there appeared
an angel unto him from heaven, strengthening him.
Jesus' guardian 'angel's were Gabriel and 'Herald' (Luk. 1:26, 24:4; Act. 1:10). Jesus had access to nothing we do not also have.
Mat 18:10 Take heed that ye despise not one of
these little ones; for I say unto you, That in heaven
their angels do always behold the face of my Father which is in heaven.
See also other examples, such as Exo. 23:20 (the Son of God, as Messenger for the Father, guarding His peoples, His body); Dan. 6:22; Psa. 34:7; Heb. 1:14. They are to "minister" to God's peoples, that have called upon the name of the LORD Jesus.
2Ki 6:16 And he answered, Fear not: for
they that be with us are more than they that be with them.
2Ki 6:17 And Elisha prayed, and said, LORD, I pray thee, open his eyes, that he may see. And the LORD opened the eyes of the young man; and he saw: and, behold, the mountain was
full of horses and chariots of fire round about Elisha.
2Ch 32:7 Be strong and courageous, be not afraid nor dismayed for the king of Assyria, nor for all the multitude that is with him: for
there be more with us than with him:
2Ch 32:8 With him is an arm of flesh; but
with us is the LORD our God to help us, and to fight our battles. And the people rested themselves upon the words of Hezekiah king of Judah.
Dan_6:22
My God hath sent his angel, and hath shut the lions' mouths, that they have not hurt me: forasmuch as before him innocency was found in me; and also before thee, O king, have I done no hurt.
Psa 34:6
This poor man cried, and the LORD heard him, and
saved him out of all his troubles.
Psa 34:7
The angel of the LORD encampeth round about them that fear him, and delivereth them.
Psa 103:20 Bless the LORD, ye
his angels, that excel in strength, that do his commandments, hearkening unto the voice of his word.
Psa 103:21 Bless ye the LORD, all ye his hosts;
ye ministers of his, that do his pleasure.
Psa 104:4 Who maketh
his angels spirits;
his ministers a flaming fire:
Mat_26:53 Thinkest thou that I cannot now
pray to my Father, and he shall presently give me more than twelve legions of angels?
Heb 1:7 And
of the angels he saith, Who maketh
his angels spirits, and
his ministers a flame of fire.
Heb_1:14 Are they not all
ministering spirits, sent forth to minister for them who shall be heirs of salvation?
Some people have had interventions from before their birth, such as Samson.
As for Michael (not to detract from OP), as a side note, see -
Michael The Archangel Who Is Like Unto God The Highest Messenger (BOOK) : Free Download, Borrow, and Streaming : Internet Archive