Is there a way to disable 2FA on my account?

Hello!

Apple cannot turn off Two-Factor for you.

"If you already use two-factor authentication, you can no longer turn it off. Certain features in the latest versions of iOS and macOS require this extra level of security, which is designed to protect your information. If you recently updated your account, you can unenroll for two weeks. Just open your enrollment confirmation email and click the link to return to your previous security settings. Keep in mind, this makes your account less secure and means that you can't use features that require higher security."

HT204915

Yes, you can change your Trusted phone number:

To use two-factor authentication, you need at least one trusted phone number on file where you can receive verification codes. Consider verifying an additional trusted phone number other than your own phone number. If your iPhone is your only trusted device and it is missing or damaged, you will be unable to receive verification codes required to access your account.

You can update your trusted phone numbers when you follow these steps:

1. Go to your Apple ID account page.
2. Sign in with your Apple ID.
3. Go to the Security section and click Edit.

If you want to add a phone number, click Add a Trusted Phone Number and enter the phone number. Choose to verify the number with a text message or automated phone call, and click Continue. To remove a trusted phone number, click  next to the phone number you want to remove.

Not if you have had it active for 2 weeks.

ASC - Late 2012 Mac mini, macOS 10.14.6; Watch, series 3 cellular, watchOS 5.3; iPad Air 2 & iPhone 8+, iOS 12.4; TV 4th Gen, tvOS 12.4;  HomePods, audioOS 12.4 and Airport Express w/ Airplay 2

Can the phone number be changed ?