To add to the excellent set of questions and considerations provided by RFC3261:
Asking that question here on the forum is a bit tricky, as the regular posters tend to have a high level of interest and/or skill in VoIP telephone technology, and enjoy tinkering with it. Some folks turn this into a hobby with a curious level of intensity or focus, and that may not describe your level of interest or technical skill. Translation: this stuff is not for everyone.
Your main goal is to keep your existing home phone number, but given that you also have a cell phone, you'd like to "cut the cord" to what is no longer a heavily-used service.
RFC3261 brought up a point worth exploring: Take a look at the current cost of your Verizon land line. Call Comcast and see what they'll negotiate, if you port your existing Verizon number to them. Usually, bundling in a "2-fer" like internet+telephone service gives you a discount on each service, so don't sign up during that sales call; take some time to do the math and compare the net cost difference if you go with Comcast, vs. staying with Verizon, vs, neither of those two.
Comcast does charge a lot of money for their telephone service, which they try to market to people who will heavily use it for unlimited calling. Pro: it is very reliable, and runs over their managed IP network, so call quality should be excellent (as long as you have excellent internet service, which sadly isn't a given everywhere). Con: it may not be worth the price (you don't need that level of service).
If you want to save money and just keep that number for occasional inbound and outbound calls and E-911 service, then you can port your existing phone number to one of the quality SIP VoIP service providers that work with OBi devices, or to Google Voice. If you choose the latter option, keep in mind that porting is more complex, because Google can't accept inbound ports from land line providers. You'd need to first port the Verizon number to a prepaid cell phone company, like AT&T GoPhone or T-Mobile, then wait a few days to a week, and then port it to GV. There is a broad range of pricing among the providers, depending on calling volume and services offered.
There is great deal of previous discussion on these topics here on the forum, so please feel free to do some time reading through the material, to answer some of the previously-answered, common questions, then come back with your next round.
