The 25-year-old replaced Roberto Firmino late in the 5-0 win at the Estadio do Dragao.
"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 the club's 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."