The fullback, on-loan at Hibs, faced Portugal stars Nani and Cristiano Ronaldo in his last international.
"Personally it was a great experience, probably one of the highlights of my career so far," said McGivern, who is expected to retain his place against Azerbaijan on Tuesday night.
"It's given me a bit of confidence. Marking two of the top wingers in the game, Nani and (especially) Ronaldo, who's one of the best players in the world along with Lionel Messi.
"If I managed to keep those two quiet enough for 90 minutes it gives me a lot of confidence for the rest of my career.
"It was a great team performance - Portugal were ranked three in the world at the time - and for us to go there and get a point was great."