Agree with Previous Contributor regarding doing this is steps.
Much has changed since the release of OS X 10.12 Sierra in 2016.
Once approaching and not yet attempted the move to Monterey macOS 12.
If this computer has an After Market Internal Drive there are times it may install Monterey and there are times it just will not.
The Monterey Installer Includes a EFI Boot ROM for the Computer ( Not the Drive ).
The Installer will verify if the Internal Drive is an Apple Original Drive
If none is found - it may baulk and refuse to install.
Then there is the Issue of Empty Space on the Drive.
Here I can not quote the exact figures for Ventura but for Big Sur macOS 11 - Apple Suggested an minimum of about 36 GB of Empty Space
The more Empty Space the Better, maybe 50 GB Empty Space
Factor in RAM - to get a reasonable lightweight usage experience - a Minimum of 8 GB RAM is suggested, 16 GB is better
Fusion Drives were good in its' day but are generally very show on anything above Big Sur macOS 11 as the newer Operating System seems to be geared towards an ALL SSD Configuration.
The above does not mean Ventura will not function but it tends to perform at a below the Users Expectations. This is by Observation Only and not first hand experience
Lastly does the User have a Rescue Plan and up to date.
3 Backups using 2 different Method and 1 Off Site incase of Natural Disasters or Un-Natural Disasters
