First of all, I welcome you in your search for truth.
I think you at least believe in the authority of Jesus Christ.
Next, the question is what the term “Church” means to Catholics. It can mean either the assembly of believers in a certain region, or the totality thereof.
The Church is also the “body of Christ”
Ephesians 1:22 And he hath subjected all things under his feet, and hath made him head over all the church, 23 Which is his body, and the fulness of him who is filled all in all.
The notions of Church include
*] an external juridical organization stemming from Christ
*] the inner attachment by grace of man with Christ, through the Holy Spirit
J.A. Moehler’s definition:
By the Church on earth Catholics understand the visible community of all the faithful, founded by Christ, in which are continued the activities developed by Him during His earthly life for the remission of sin and for the salvation of mankind under the direction of His Spirit until the end of the world, by means of a continuous uninterrupted Apostolate ordained by Him, and by which, in the course of time, all peoples will be brought back to God …
The following passage indicates that the believers needed a leader:
Matthew 9:36 And seeing the multitudes, he had compassion on them: because they were distressed, and lying like sheep that have no shepherd.
This passage shows that Christ appointed Peter to the task in His place:
John 21:17 … And he said to him: Lord, thou knowest all things: thou knowest that I love thee. He said to him: Feed my sheep.
This passage shows that we must adhere to the shepherd of our district
1 Peter 2:25 For you were as sheep going astray; but you are now converted to the shepherd and bishop of your souls.
Jesus sent His Apostles out to do what He had done. The Church is doing that in preaching, Sacraments, and jurisdiction.
That the Apostles had an office that was passed on can be seen in this passage:
Acts 1:15 In those days Peter rising up in the midst of the brethren, said: … 16 Men, brethren, the scripture must needs be fulfilled, which the Holy Ghost spoke before by the mouth of David concerning Judas, who was the leader of them that apprehended Jesus: 17 Who was numbered with us, and had obtained part of this ministry. 18 And he indeed hath possessed a field of the reward of iniquity, and being hanged, burst asunder in the midst: and all his bowels gushed out. 19 And it became known to all the inhabitants of Jerusalem: so that the same field was called in their tongue, Haceldama, that is to say, The field of blood. 20 For it is written in the book of Psalms: Let their habitation become desolate, and let there be none to dwell therein. And his bishopric let another take. 21 Wherefore of these men who have companied with us all the time that the Lord Jesus came in and went out among us, 22 Beginning from the baptism of John, until the day wherein he was taken up from us, one of these must be made a witness with us of his resurrection. 23 And they appointed two, Joseph, called Barsabas, who was surnamed Justus, and Matthias. 24 And praying, they said: Thou, Lord, who knowest the hearts of all men, shew whether of these two thou hast chosen, 25 To take the place of this ministry and apostleship, from which Judas hath by transgression fallen, that he might go to his own place. 26 And they gave them lots, and the lot fell upon Matthias, and he was numbered with the eleven apostles.
Now, we know Christ started His Church and promised that it would endure:
Matthew 16:18 And I say to thee: That thou art Peter; and upon this rock I will build my church, and the gates of hell shall not prevail against it.
He also gave it authority
Luke 10:16 He that heareth you, heareth me; and he that despiseth you, despiseth me; and he that despiseth me, despiseth him that sent me.
Romans 1:5 By whom we have received grace and apostleship for obedience to the faith, in all nations, for his name;
1 Cor 4:1 Let a man so account of us as of the ministers of Christ, and the dispensers of the mysteries of God.
2 Cor 5:18 But all things are of God, who hath reconciled us to himself by Christ; and hath given to us the ministry of reconciliation. 19 For God indeed was in Christ, reconciling the world to himself, not imputing to them their sins; and he hath placed in us the word of reconciliation. 20 For Christ therefore we are ambassadors, God as it were exhorting by us. For Christ, we beseech you, be reconciled to God.