Ings, whose Liverpool career has been hindered by injury, made his impact in the game with an assist for Sadio Mane's third goal.
"It was one of those things where you watch it as a kid and have a dream of playing in the competition," Ings told Liverpool's official website.
"So to come on and make my debut was a huge moment for me. I was very, very happy. But the most important thing was the 5-0 win - away at Porto, it's a huge result.
"To be part of this group in a competition like that is huge for me, from the levels that I've come from over the years.
"It was a huge moment but something I want to build on. I want to stay around it with the lads and try to win as many games as we can and see how far we can go in the competition."
The two sides will meet at Anfield for the return fixture on Tuesday, March 6.