...I need to know what type of scanner I need and also what frequencies/channels I need to input into it when I do get one to listen to police...
I just did a quick look at the database. Looks like your primary monitoring target will be the
Sacramento Regional Comm Authority which appears to be an 800 MHz , P25 , Phase 1 system. That's a good thing in that there are a lot of scanners that will handle P25 Phase 1.
I'll recommend the UnidenBCD325P2 (
https://uniden.com/products/handheld-trunktracker-v-scanner). You'll also need/want programming software. I like Proscan software. It's full featured and well supported, including support here on RR. It can import the system information directly from the RR database which makes programming a trunked system a lot easier.
In addition the the Sac Regional Comm Authority, you'll probably want to monitor CalFire, which is VHF high band conventional and CHP which is (mostly) VHF low band conventional. The BCD325P2 will handle all of these.
Since you said you're new to scanning, I'll also recommend shopping around for whatever scanner you decide upon. Supplies are short and it's a seller's market. Stay with major name sellers and beware of any deals that sound too good. You can always ask here for merchant reviews. You may be more comfortable with this first purchase by visiting a brick & mortar store. I'm not familiar with merchants in the Sacramento area, but Ham Radio Outlet (HRO) is a well known and respected vendor and has its headquarters store in Walnut Creek.