Hello Grandmarquis0401,
Ensuring you're signed in to the correct Apple ID on your device is important, and you've come to a great place for help. When you go in to Settings > [your name] > Media & Purchases, then tap View Account does the yahoo Apple ID show as being signed in? If so, are you being prompted to sign in to the gmail account when attempting to update applications?
If you're prompted to sign in to the gmail Apple ID when updating apps that would indicate that some apps on your iPhone were originally downloaded with that older account. There are a couple of options for preventing this popup from appearing, or being able to move past the popup when it appears.
You can delete the apps that were downloaded with that older account, and redownload the apps with the newer Apple ID you're currently signed in to. Another option would be regain access to your older Apple ID. If you forgot the Apple ID password you can find the steps for resetting the password below.
If you forgot your Apple ID password
If you know the password, and have two-factor authentication enabled, but unable to retrieve a verification code you can request try to obtain a verification using the steps in the first article linked below. If you're unable to reset the password or obtain a verification code requesting account recovery is the next step.
Get a verification code and sign in with two-factor authentication
How to use account recovery when you can't reset your Apple ID password
Have a great day!