Hey BD79,
We’d be happy to help out. It’s not entirely clear what you mean by it not allowing you to use a symbol when creating your new password, but you should absolutely be able to. Perhaps the symbol you used or the sequencing involing those symbols was the issue, but you’re more than welcome to use a password with one and you can change your password as many times as needed.
For help with doing so, please review these steps:
Change your Apple ID password on your iPhone, iPad, iPod touch, or Apple Watch
1. Tap Settings > your name > Password & Security.
2. Tap Change Password.
3. Enter your current password or device passcode, then enter a new password and confirm the new password. Forgot your password?
4. Tap Change or Change Password.
This is outlined further here: Change your Apple ID password - Apple Support
We hope this helps out.
Take care!