Wallace, a former US college basketballer from North Carolina, was signed by North in December for the next two seasons after impressing in a 10-day trial with the club.
Wallace, 196cm and 102kg, first came to the Roos' attention at last October's NAB AFL Draft Combine, when as one of 10 international athletes to test he showed outstanding athleticism and speed.
But Wallace told SEN radio on Wednesday that the start to his AFL life had been tough.
"It's a challenge, it's a challenge every day," Wallace said.
"At the same time it's fun. I'm enjoying myself, learning a new sport, I'm meeting new people, learning an entirely different new culture.
"I described it yesterday with the guys as a beautiful struggle so we'll see how it turns out."
Speaking from North's first-year player camp in Tasmania, Wallace said his biggest challenge would be adjusting to the amount of running required in the AFL.
"The field is huge, (it is) probably the most aerobic game in the world I would say, having experimented with a number of sports," Wallace said.
Wallace said he was working "all day" to develop his skills with the oval Australian football, completing 200-300 kicks a day and 400 handballs.
"[I want to] really try to find my niche in the game as soon as I learn the game and then add some of my own aspects to the game that I got from basketball," Wallace said.
Wallace said he'd been told his niche might be as an athletic ruckman/forward.
Nick Bowen covers North Melbourne news for AFL.com.au. Follow him on Twitter: @AFL_Nick