two phone numbers on apple id

recently i got a new phone and transferred my data from my old phone to my new one. my phone number stayed the same and i can’t text off of that number too but when sharing my phone number it shows my moms number as my number if that makes sense? when i got “this iphone” and it shows my number it shows hers. when i go to messages and choose the numbers and address i can send and receive messages from, MY phone number and apple id are selected but my moms number is on there too with a loading cog(?) on it. how do i fix this? (i switched from iphone 6s to xr)