Honestly there’s no correct way to pull cards. Technically with the Tarot there’s no “correct” way to do anything.
Different methods work for different people. Some readers fan out the deck and pick whatever card calls to them. Others grab cards from various spots in the deck, top, middle, bottom, wherever. Then you’ve got people who shuffle until cards jump out. Those are called jumpers in tarot circles.
Me? I shuffle well, divide into three piles, restack, and pull from the top. But really, just do what feels right. Your technique doesn’t matter that much.