How can I reset my Apple ID password with my old number?

Your number should not prevent you from changing your password if you still know the current one.

If the number is the one you use for 2 Factor authentication codes, and you no longer remember your password, you won't be able to get the codes, and as such will need to request an account recovery procedure from Apple support directly. click here ➜ How to use account recovery when you can’t reset your Apple ID password - Apple Support

With that said, you should never use your own number as the trusted number to get codes. It should always be number you have access to even when you don't have access to your iPhone. It can be a land line or even an android device from a friend or relative such that you can get there codes when your own iPhone is not available or your number no longer works. It should also be kept updated as necessary.

click here ➜ Two-factor authentication for Apple ID and Trusted Phone Numbers - Apple Support

Hello Wh0s-niki, If you don’t have a trusted device because your Apple Id is trusted to a phone number you know longer have you can try reseting on the WEB. It takes a little longer than if you have a trusted device.

https://iforgot.apple.com/password/verify/appleid