I can’t log in to my Apple ID because I changed my cell phone number

Why? Is it asking you for the number you set as a trusted number? Trusted number should not be be your own number as it entirely negates the possibility of accessing your account when you don't have access to your phone. It should be a friend or relatives number (iPhone, android or even landline) so you can get the Two-Factor Authentication code.

The Two Factor authentication code should be sent to trusted devices directly without requiring your phone number.

If you have no other trusted device and cannot receive the trusted number, then you will need to apply for Account recovery to regain access to your account.

Link-> How to use account recovery when you can’t reset your Apple ID password - Apple Support

See if anything here helps.  If necessary, you can use account recovery as explained in the link at bottom of the article.

Verification code - how to get one and sign in with two-factor authentication.   *

If you can get a code and sign in, you need to change/add the number on your Apple ID. Look in the Security section when signed in online. You may have to add the new number before you can remove the old number. After the change, allow up to 24 hours for the change to sync. Before trying to make the change, sign out of Messages/FaceTime on all devices/computers.

Apple ID - Manage

Hi Ruiz2513,

welcome to the Apple Community

Re: I can’t log in to my Apple ID because I changed my cell phone number

You. might want to carefully read Apple Support's authentication article:s to see if there's another way you can use.

Eg: Do you also have a computer / other device listed in your Apple ID, where you could receive a verification code.

Manage two-factor authentication for your Apple ID from iPhone – Apple Support

and

Two-factor authentication for Apple ID – Apple Support

Eg says:

"If I can't sign in, how do I regain access to my account?

If you can’t sign in, access a trusted device, or receive verification codes,

you can request account recovery to regain access to your account.

Account recovery is an automatic process designed to get you back in to your account as quickly as possible

while denying access to anyone who might be pretending to be you.

It may take a few days — or longer — depending on what specific account information you can provide

to verify your identity.

If you generated a recovery key, you can use your recovery key to regain access to your account instead. 

Learn more about using a recovery key. "

All the best :-)