Galatians 1

Before Paul mentions his disagreement with Peter (chapter 2), he shares how each actually learned the gospel of Jesus Christ -

"But I certify you, brethren, that the gospel which was preached of me is not after man.
12 For I neither received it of man, neither was I taught it, but by the revelation of Jesus Christ."  (Galatians 1:11–12)

Explaining after his conversion -

"Neither went I up to Jerusalem to them which were apostles before me; but I went into Arabia, and returned again unto Damascus.
18 Then after three years I went up to Jerusalem to see Peter, and abode with him fifteen days.
19 But other of the apostles saw I none, save James the Lord’s brother.
20 Now the things which I write unto you, behold, before God, I lie not."  (Galatians 1:17–20)

It appears to me that after his vision on the road to damascus, he spent a lot of time studying, praying, and being taught concerning the gospel of Jesus Christ.