The England international was mired in controversy after being alleged to have hosted a “sex party” in April
Walker was forced to issue an apology in April for hosting an alleged “sex party” in which the defender invited two women to his home.
The 30-year-old again broke lockdown rules in May when he visited his sister and his parents in Sheffield.
Walker addressed those instances in an interview on BBC Radio 5 on Tuesday, admitting that he needed to be a better role model in his position as a public figure.
“I reflect on my decision making. They were bad decisions from me at an important time for the country,” Walker said. “I take full responsibility for that but I’m moving on now.
“Me and the boss [England manager Gareth Southgate] spoke after the lockdown incidents and, you know, he assured me that we all make mistakes.
“Obviously, mine were on a bigger scale and gets magnified with me being in the public eye and a role model, so I have to take full responsibility for my actions, which I have done.”
Walker was backed by his manager Pep Guardiola during the controversy, with the Spaniard saying his defender had “made a brave statement.”
“At 19 when I first joined in the England team, I’d have said no chance,” Walker, who currently has 47 caps, said of reaching the milestone.
“But now I think it’s possible. Obviously I’ve only got three more caps to get to that and that’s a big goal of mine.
“Not many players can say that they’ve got 50 caps for their country and especially for England.
“Hopefully I can be a part of that club and it’d be a very proud moment for me and my family.”
The Three Lions begin Nations League play when they travel to face Iceland in Reykjavik on Saturday, before another away fixture against Denmark on September 8.