Hi Enolanch1,
welcome to the Apple (user-to-user) Community!
Re: "Unable to change my password"
Wondering which MacBook Pro model (Year) you use, and which MacOS version is installed.
(Your post seems to say MacOS version 10.13 (High Sierra) if that hasn't been updated.
Eg: For an older model / with macOS Mojave (MacOS 10.14.6) or earlier: How to:
Change or reset the password of a macOS user account in macOS Mojave or earlier - Apple Support
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Else: For a Mac using MacOS Catalina (Mac OS 10.15.7) or later:
See what to do: If you forgot your Mac login password
https://support.apple.com//102633
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Trouble-shooting if necessary:
What to do: If you can't reset your Mac login password
https://support.apple.com/HT212190
More help / support / info / contact options etc. if needed:
MacBook Pro Support website:
MacBook Pro - Official Apple Support
All the best :-)