"John's Baptism" is specifically described this way several times in the NT, always in a way that distinguishes it from the fuller revelation given by Jesus. See Matt 21:25, Mark 11:30, Luke 7:29, 30, 20:4, Acts 18:25, Acts 19:3, 4, etc.
The last two of these draws the distinction between the two ideas well:
Acts 18:25, 26 - He [Apollos] had been instructed in the way of the
Lord and was fervent in spirit. He spoke and taught accurately about
Jesus, though he knew only the baptism of John. And he began to
speak boldly in the synagogue. When Priscilla and Aquila heard him,
they took him in and explained to him the way of God more
accurately.
More information is given in the next chapter of acts 19:
1 While Apollos was at Corinth, Paul passed through the interior and came to Ephesus. There he found some disciples 2 and asked
them, “Did you receive the Holy Spirit when you became believers?”
“No,” they answered, “we have not even heard that there is a Holy
Spirit.”
3 “Into what, then, were you baptized?” Paul asked.
“The baptism of John,” they replied.
4 Paul explained: “John’s baptism was a baptism of repentance. He told the people to believe in the One coming after him, that is, in
Jesus.”
5 On hearing this, they were baptized into the name of the Lord Jesus. 6 And when Paul laid his hands on them, the Holy Spirit
came upon them, and they spoke in tongues and prophesied. 7 There
were about twelve men in all.
That is, John's baptism was given as a symbol of repentance and conversion = dedication of the life to God and marks the beginning of this life dedicated to God's service.
Jesus and the apostles took this same idea and extended it to include, in addition to all the above, the point at which the new Christian should receive the Holy Spirit, Matt 3:11, Mark 1:8, Luke 3:16, Acts 1:5, 2:38, 8:12-16, 10:47, 48, 11:16, 19:4, 5.