

Most cookies don’t store any data themselves. Instead it is a session/device token that tells googles servers what device is connecting and then they look up the data they have about you server side. Cookies can store more than that situationally but that is the most common use.
To get what data Google has on you check out Google takeout and you can get a “full” export of what data has been gathered.
Wireguard could be helpful if you used a SSL terminating proxy in front of it but then you have to know the data format to parse it. So unless you are a researcher it is a long path ahead of you without any OOTB tools to do it for you.