New iPhone X , traded in a 7

At the Apple store the woman that put my x together was awesome, all my apps, photos,contacts etc was very pleased, I go home and go to log into my yahoo mail acc put in my user name and it says , open your yahoo acc page and click on the site key !! I can’t get on acc Page it won’t let me long in till I click on some acc key. Then it wants to text me a code , well I moved out of state 6 months ago and changed my phone number so I can’t get a text , it wants to send to old yahoo mail acc but it’s been way over a yr so I guess it’s be deactivated??? What do I do ? I do everything through that emai, bills,meds VA , I’m a retired vet . On my new phone in settings it has the right email user name I didn’t put it there it done it it’s self when cutie transferred everything ... it’s been sents last wensday and I need to see where I’m at on receiving things/sending to my dr. I’m lost, well I’ve been lost for Yrs but that’s another story. Lol. Help me Obie one