It is best to have a mix of cameras, each one selected for the goal of the camera.
I have some varifocals for IDENTIFY at distance and pinch points, and OVERVIEW cameras so I can see what is going on with one field of view.
As far as cameras, without knowing what your goals of the camera is, this thread is used as the go to for the new person here outlining the commonly recommended cameras (along with Amazon links) based on distance to
IDENTIFY that represent the
overall best value/best bang for the buck in terms of price and performance day and night. It might be a 2MP camera in some instances. Many here feel 4MP is the current sweet spot for these cameras.
The Importance of Focal Length over MP in camera selection
And coupled with that thread is this great thread which will show why all of the same 2.8 or 3.6mm cameras is the wrong choice (these are the common focal lengths consumer brands sell):
i-want-2-8mm-cameras-everywhere-to-see-everything-this-is-why-you-need-specific-fovs-with-purposeful-focal-lengths.70053/
We would encourage you to look at those threads in detail.
It will probably raise more questions than answers LOL.