Acts 11:15 As I began to speak, the Holy Spirit came on them as he had come on us at the beginning. 16 Then I remembered what the Lord had said: John baptized with water, but you will be baptized with the Holy Spirit. 17 So if God gave them the same gift he gave us who believed in the Lord Jesus Christ, who was I to think that I could stand in Gods way?
This one notes the difference between Baptism with Water and Baptism with The Holy Spirit:
Acts 8: 14 When the apostles in Jerusalem heard that Samaria had accepted the word of God, they sent Peter and John to Samaria. 15 When they arrived, they prayed for the new believers there that they might receive the Holy Spirit, 16 because the Holy Spirit had not yet come on any of them; they had simply been baptized in the name of the Lord Jesus. 17 Then Peter and John placed their hands on them, and they received the Holy Spirit.
Water is not necessary for Baptism with the Holy Spirit
Acts 1: 5 For John baptized with water, but in a few days you will be baptized with the Holy Spirit.
6 Then they gathered around him and asked him, Lord, are you at this time going to restore the kingdom to Israel?
7 He said to them: It is not for you to know the times or dates the Father has set by his own authority. 8 But you will receive power when the Holy Spirit comes on you; and you will be my witnesses in Jerusalem, and in all Judea and Samaria, and to the ends of the earth.
I say this more from experience than reading the scriptures, but I find the scriptures very supporting of my experience.
There is a big difference between being Baptized with the Spirit and being Baptized with Water. The water is merely a metaphor for the cleansing that takes place in order for the Holy Spirit to enter a person. While it is important, it is not the end result desired. Baptism with water is not necessary for Baptism with the Holy Spirit.
Acts 8 and 11 are describing Confirmation which is in addition to Baptism. This in no way negates the necessity of Baptism. In Acts 8 it explicitly says that they were previously baptized. In Acts 1 Jesus is foretelling the descent of the Holy Spirit at Pentecost. It is because of this descent that the church can administer the sacraments and teach with authority. Welcome to the Catholic Church!