Since baptism is a symbolic identification of the believer with the death, burial, and resurrection of the Lord Jesus Christ, the first real baptism was the crucifixion. Because of this, John the Baptist's baptisms don't count as "full" baptisms. His was a baptism of repentance but baptism into Christ leads to newness of life.
Matthew 20:22 But Jesus answered and said, Ye know not what ye ask. Are ye able to drink of the cup that I shall drink of, and to be baptized with the baptism that I am baptized with?
Luke 12:50 I have a terrible baptism of suffering ahead of Me, and I am under a heavy burden until it is accomplished.
Romans 6:3-6 Do you not know that all of us who have been baptized into Christ Jesus were baptized into his death? 4 We were buried therefore with him by baptism into death, so that as Christ was raised from the dead by the glory of the Father, we too might walk in newness of life. 5 For if we have been united with him in a death like his, we shall certainly be united with him in a resurrection like his. 6 We know that our old self was crucified with him so that the sinful body might be destroyed, and we might no longer be enslaved to sin.
I hope you have found this helpful.