Verses in question:
Genesis 11:8-9: “So the Lord scattered them abroad from there over the face of the whole earth; and they stopped building the city. Therefore its name was called Babel, because there the Lord confused the language of the whole earth; and from there the Lord scattered them abroad over the face of the whole earth.”
1 Corinthians 14:33: “For God is not a God of confusion but of peace, as in all the churches of the saints.”
1 Corinthians 14:33 is referring to the gift of tongues in the early churches. Because outsiders would visit these churches confusion would manifest from them hearing different languages. Paul is saying that the objective of speaking in tongues was not to produce confusion among the hearers, which would mean that they would not understand the gospel that testifies about Jesus.
In Genesis 11:8-9 the people were trying to construct a tower that would “reach into heaven.” However, God accepted their challenge and decided to confuse their languages. This bespeaks a different context to the one we find within 1 Corinthians. God is not the author of confusion and prefers peace but, alternatively, he can confuse if he wants to in order to achieve a purpose.