Hope it turns out well for you.
I've been in more or less the same situation as you for most of my life. I knew my dad growing up, but never really spent time with him, so I never really knew him or even felt comfortable with calling him my dad. My parents kept arguing amongst themselves basically at my expense, and with enough time the distance between my father and I never recovered.
He eventually did come back into contact with me recently, and I was cautious at first.

I was a bit standoffish, but not in a cold manner, rather I just stuck to listening to my dad and what he had to say. Eventually, I just started calling him pops and checking up on him more often, and you could tell it lifted a lot of his guilt off his mind, which I felt good about.
I'm fortunate that I was able to so easily forgive, and I hope that's the case for you. If you can, get the answers you want from your dad, you deserve them, and if he's trying to really make up for that lost time, don't go too hard on em either man, cause its killer having to be the one that makes your dad feel like he's fallen short. Again, only if you feel like he deserve as much tho, cause if he does, you're going to feel good when you extend your love and support out to him
Good luck breh.