A camera by the front door is one of the simplest ways to know a man living alone is home and fine without calling every evening. It is also the kind of thing a proud father can feel watched by if it is set up badly or handed over without a word. Install it in this order, and do the last step with him in the kitchen, not behind his back.
Local option: New Plan Care gives families in the St. Louis area in-home help so a parent can stay home: companionship, help with bathing and dressing, meals, and overnight care. Call (314) 405-0887.
Before the ladder
Check the Wi-Fi signal at the exact spot you plan to mount the camera. Use your phone and stand where the camera will sit. If the bars are weak there, the video will freeze or drop out at the worst moment, and a router move or a small extender may be needed first. Decide whether the camera will be battery powered or wired to the existing doorbell circuit. If it is wired and you are not sure how to shut off that circuit safely, hire an electrician rather than guessing.
Mount it where it sees the steps
Aim the camera at the steps and the door, not at the street or the neighbor's windows. Keep the height low enough to see faces and high enough to avoid tampering. Use the screws and anchors that come in the box, and drill into the frame or a solid part of the wall rather than thin trim. Check that the bracket is level before you tighten the last screw, because a crooked camera gives you a crooked view forever.
Power it and pair the app
Charge the battery or switch on the wired power. Install the app on your phone first and create the account yourself, so you control the login. Then add his phone or a second login as a shared user if you want him to see the alerts too. Write the account email and the password in the family folder, and keep a copy somewhere he can find it without asking you.
Test the view
Walk up the steps and stand at the door. Check the video at the front door and the steps, the night view, and the sound. Adjust the motion zones so the camera does not trigger every time a car passes on the street. Wait for the alert to arrive on your phone. If nothing comes through, check the notification settings in the app and in the phone's own settings before you decide the camera is broken.
Hand it over with him
Sit down with him and show him the live view on the phone. Explain what it records, how long it keeps the clips, and whether there is a monthly storage plan he would need to pay for. Tell him plainly that it is there so you know he is home, not so someone watches him all day. Ask him whether he is comfortable with it, and listen to the answer. If he says no to one part, such as the audio, turn that part off.
Do not use the camera to check on him without telling him you do. It works best when he knows exactly what is on the screen and who can see it.
Tonight
Stand at the spot where the camera will go and check the Wi-Fi bars. Charge the battery, or find the breaker for the doorbell circuit if the camera will be wired. Then call him and say you are coming by to put a camera up, and ask whether there is a time that suits him.