Cheers and welcome to Bike Forums.
In my opinion, forget about the various marketing terms (road bike, cyclocross, hybrid, MTB) at first and concentrate on what you want to do with the bike. I get the impression you would mostly be riding on road. Front suspension (again in my opinion) is dead weight and just another maintenance point in that use, for example.
Regarding speed on road use, a lot depends on tyres. If you use relatively thin, slick tyres, and keep them pumped up close to max. suggested pressures, any bike will feel faster. Still, the main factor in speed is the engine - you.
Some other points to consider in addition to the surface you'll be riding on: will you be riding in all kinds of weather, year round? If yes, you should consider proper fenders (well, maybe less so in California
). Do you need to haul groceries or other stuff? If yes, consider rear and maybe front racks + panniers, or even a trailer. Will you be riding at night? You'll need lights, reflectors etc.
When you have an idea what you need (or want), you can start looking at the various "families" of bikes to see how they suit you. There are big grey areas in between them, a bike sold as an MTB can be equipped with lighter tyres, racks, fenders etc. That will essentially make it a "hybrid bike". But if hybrid is what you want, it will practically always be cheaper to buy one ready-made, rather than build it up yourself.
One approach is to just buy a relatively cheap entry bike that fits what you currently think you'd use it for. Then ride it to bits and see what you like and dislike about it. You will in all likelihood be in the bike shop again pretty soon, but this time you will know fairly well what is important to you and what is not. That's something nobody else will be able to tell you.