That is not correct. The order in Scripture is first conversion, then baptism.The order of the baptisms can go either way.
BEFORE. Then they that gladly received his word were baptized...The outpouring at Pentecost - Acts chapter two - AFTER
"Gladly received his word" = believed the Gospel = were saved = received the Holy Spirit
BEFORE. But when they believed Philip preaching the things concerning the kingdom of God, and the name of Jesus Christ, they were baptized, both men and women.The believers in Samaria - Acts 8:14-17 - AFTER
"Believed Philip" = believed the Gospel = were saved = received the Holy Spirit
BEFORE. ...that they should believe on him which should come after him, that is, on Christ Jesus. When they heard this, they were baptized in the name of the Lord Jesus.The disciples in Ephesus - Acts chapter nineteen - AFTER
"That they should believe on Him" = believed the Gospel = were saved = received the Holy Spirit.
After that Paul his hands upon them. This was not usual, and it was to enable them to speak in tongues and prophesy. It could be because before this they had not heard of the Holy Ghost and they needed to witness the power of the Spirit.