That's not a good choice for pfsense for a few reasons...
Modern PFSense requires a CPU with AES-NI extensions: pfSense hardware 2021 (3 router recommendations)
. You can check if a Intel CPU has AES-NI on Intel's ARK listing. Core2Duo CPUs are much too old.
The other reason is power. If you want to use this as your actual router, it's is going to be running 24/7, and a Core2Duo machine is going to draw a lot of power whilst running, even at idle.
Ideally you want to be looking for something with a fairly modern Atom/Pentium CPU that can utilise low-power idle states. Not sure what it's like in your country at the moment but here energy prices are crazy and paying more for a lower-power CPU will payback itself quickly.
PFSense doesn't require much CPU or RAM for a basic install, it really depends on your bandwidth and what you plan on doing with it (IDS such as Snort/suricata will use a lot more CPU, as will VPN tunnels)
Sophos Home is limited to a max number of CPU cores - less cores will work.
But the same guidelines for PFSense apply to basically any other router distro such as Sophos XG, OPNSense, Untangle, IPFire etc...