Paul asserts Galatians 1:18-20 that he saw none of the apostles except Cephas and James the Lord's brother. Acts 9:26-30 (27) But Barnabas brings Paul to the apostles and brought to the Apostles & moving / preaching freely (arguably could be only 2, but walking and preaching freely). These 2 would indicate the same event as Paul has not been accepted. Then you have Galatians 2:1-10 states this time with Barnabas this would imply that Barnabas was not with him in Acts 9.
Galatians 2:1-2 1 Then after fourteen years, I went up again to Jerusalem, this time with Barnabas. I took Titus along also. 2 I went in response to a revelation and, meeting privately with those esteemed as leaders, I presented to them the gospel that I preach among the Gentiles. I wanted to be sure I was not running and had not been running my race in vain.
Galatians 1:18-20 18 Then after three years, I went up to Jerusalem to get acquainted with Cephas[a] and stayed with him fifteen days. 19 I saw none of the other apostles—only James, the Lord’s brother. 20 I assure you before God that what I am writing you is no lie.
Acts 9:26-30 Yet Barnabas says - 26 When he came to Jerusalem, he tried to join the disciples, but they were all afraid of him, not believing that he really was a disciple. 27 But Barnabas took him and brought him to the apostles. He told them how Saul on his journey had seen the Lord and that the Lord had spoken to him, and how in Damascus he had preached fearlessly in the name of Jesus. 28 So Saul stayed with them and moved about freely in Jerusalem, speaking boldly in the name of the Lord. 29 He talked and debated with the Hellenistic Jews,[a] but they tried to kill him. 30 When the believers learned of this, they took him down to Caesarea and sent him off to Tarsus.