Closure talk post-breakup?

Got broken up around 1 month ago over text. Was too heartbroken to see him in-person. Went immediately NC after to 1) respect his decision, and 2) heal. I want to have a closure talk, maybe in some time, to understand what went wrong, and how to be a better partner.

I know i did my best, and that it's not about getting back together, even though i deeply love this person. It's not even about telling him about things that hurt me, because we're not in a relation anymore. When we broke up, he wanted to meet up, and offered me to contact him whenever for closure. I just feel like that it would be good to know some things I havent paid attention or even defaults I could work on. So I can have better relationships later.

He's my first love and relationship, even tho im mid twenties. It was super hard processing the breakup as I dont have experience, i truly love him and i thought he was the one. But that's also the reason I feel like reaching out could help. I dont wanna go ever again through this hell.