Congratulations on your new fid. My only advice would be to back off and take it slow. My sun conure was aggressive when I first adopted him (age 5). I think it was because he was scared and missed his original mum, but he lunged and threatened to bite, but never actually followed through, probably because I never gave him the opportunity to reach my skin on those early days / weeks. He also refused to leave his cage, even though I always left his cage door open if I was in the room. I started off just offering treats in his treat bowl, making sure he saw it was me dropping them in there. Progressed to him taking them from my hand through the bars. If he lunged, I took that as a sign I was going too fast and went back to dropping them in his treat bowl. Once he was reliably taking them from my hand without lunging, only then did I move onto clicker training. He already knew "step up" from his original mum, so we started there. As he still refused to leave his cage, we did this from inside the cage. That may not work for all birds, as lots don't like hands in their cage - but it was ok for us. Anyway we did "step up", "click" = reward, then "down" "click" = reward. At first, he was rewarded for just being prepared to step towards me, then one claw on me, finally two claws. I always immediately did the "down" command, so he'd see that agreeing to step up didn't mean the human was going to take him away from his safe place (cage). When he was reliably doing that, I positioned his play stand so that a branch stuck into his cage. To get the treat he now had to step onto the play stand first and walk outside the cage before stepping up.
In between the clicker training, I sat watching TV in the same room, but not looking at him, with my other bird crawling happily all over me. I hoped this showed him I was safe and not a predator.
Eventually he flew from his open cage to me and our bond was complete. From that day, he decided I was his. All this took about 5 months- so patience is required.
Try not to get into a situation where your new bird bites you. You don't want to teach him that biting is the way he can get want he wants. Try to do everything with his consent and with positive reinforcement.
I swear it was the clicker that made the difference. Just don't rush it. As yours has already bitten you, I would do clicker target training, instead of "step up" training. Only move onto to step up once you're fairly confident of no bite. It may take a while to learn his body language.
Good luck