My first comment is that cameras are for surveillance. An alarm system, preferably wired, is for security.
Have a look in the Wiki in the blue bar at the top of the page on a real computer, not phone or tablet. There's tons of solid information and advice in there. After you've digested some of that you'll be in a better position to understand what a decent system is and how to build one up.
Welcome. I came in knowing 0.
I had purchased a DVR to update the Old DVR at my Job. I inherited an old Black and white CCTV system.
Then the questions and google searched started. then That of course, lead me here.
to add to the painful ignorance. My housemate stopped in a Costco Aisle full of Home security cam systems.
Knowing Jack shit, we decided on the Nightowl 5Mp 8 channel recorder, included was four overpriced underhwelmingly cheap cameras.
And then you learn they scare you with offering additional camera's and other camers may not work with your new system.
I installed it bumbled through the skimpy User Interface, and when looking for motion events, I called Bullshit on the whole thing.
What a piece of crap.
Thus began another long journey up the Blue Iris ladder to a functional and fast and pleasant piece of software which transformed my whole opinion of "what could be"
I'm just a Joe 5 pack ladder climbing monkey maintenance man. but I'm running 2 BI systems now.
Use https://calculator.ipvm.com to pull up a satellite view of your house/property and overlay any camera model you are considering purchasing. It will give you a lot of information and insight into how the camera will perform. Pay close attention to the PPF (pixels per face) number at various distances away from the camera mounting location as it is directly related to the ability to identify a stranger from the cameras footage. You really want to stay above 100 PPF to get clear enough footage.
Now PPF is only one part of the overall story. If the camera is incapable of capturing footage that isn't blurry or ghosting at night, it doesn't matter how many PPF you have, the image will be unusable. Don't buy into a camera's marketing material because they will never show you footage from low light/night time of a moving subject which is the most important time of the day you want your cameras to be working. Most crime happens at night - if your camera isn't capable of producing clear images at night then you wasted your money purchasing it.