There are a lot of things that I would take back. I have tried to not live my life focused on regret, but there are many things I said that I would take back and many actions I would do differently. Mostly they are things that I said or did to family members or close friends. Some things haunt me to this day. Some things I know that had I done them differently, my life may have turned out differently.
Does that necessarily mean that I did it wrong? No. It just means that as I look back at my life, I see where the path I took may not have been the best path to take, or it was a path that has possibly added to my stress and affected my relationships with others.
Should you live your life with regret? Maybe. To the level that it consumes you day and night? Definitely not. Some would say that you need to seek forgiveness for your actions and move on. While you can seek forgiveness, you still need to accept responsibility for your actions and learn from them.