Changing emails, names, etc.

Hello I have recently transitioned, but I don't know what to do with my emails.

My old email is just my deadname and a number and I used this email for like 20 years for everything.

I really don't want to keep using it I made a new email but now I have to change all my subscriptions and everything.

Does anyone know if I can just change my outlook email address or do I need to make a new email?