What do I(F19) do he told me about his his(M19) past

He used to be a coworker of mine, but he left because his schedule didn't fit the job (I am also on the verge of quitting or getting fired after learning that it's a Devil Corps job).

However, we end up talking, and he takes me on two dates before asking me out. I should also mention that I recently ended a relationship with my ex because of his negligence and lack of responsibility regarding my severe allergies, which I had repeatedly warned him about. He was also emotionally abusive and on the verge of becoming physically abusive.

He confessed RECENTLY that he caught feelings for me while I was in the relationship but didn't say anything because he wanted to be respectful. So then we ended up talking, and he would walk me up to my apartment to keep me safe from my ex. He gave me rides home when he used to work with me, but the thing is this current guy mentioned having to change due to his past. He had drinking problems and got into a lot of fights. He said he got involved with the wrong crowd, and people always wanted to mess with him back then, and he got bullied, and because his dad was a boxer, for some reason, people wanted to fight him, so he had to learn to toughen up. He also said his dad used to force alcohol down his throat, and then he said he learned it was wrong and changed. He's been 3 years sober, but he also said that he wants to improve even more. How should I feel about this?

So far he hasn't done anything; this is all he's told me when we played 21 questions.

Tl;dr I found out he used to drink and get into fights when he was in school, and now he says he's changed because he realized it was wrong and is now three years sober.