Hoy! Welcome!
I’m not much of a cock connoisseur but you seem to have pretty decent starting measurements. As far as gains go…
1/2” of length is pretty reasonable and most guys can gain this much
1” of length is going to take quite a bit more effort and consistency but it is not unheard of.
2” of length is going to mean giving up your social life as this is a milestone rare enough to merit its own threads.
3” of length you better be self-employed. This is a rarity. I believe there are less than 10 people who have gained this much and all of them went well above and beyond the normal commitment most guys make to this.