As a street medic:
The first few days will hurt like fuck. Paracetamol and ibuprofen both help, but ideally only use ibuprofen after the first 48 hours (cos it can slow down healing within that period.) If there's swelling during this period, do the ice peas trick.
The ribs should heal by themselves in a few weeks, and broken ribs have a low chance of infection. You can help by trying to sleep sitting upright for a few days, or at least more upright than you usually do. Try to avoid sleeping in a foetal position, and try not to lie down that much while awake. You want to be vertical as often as possible.
Get into the habit of taking deep, slow breaths regularly, ideally hourly. Yes, it'll hurt at first. It'll help it heal. You want to get as much air in your lungs as possible to keep them healthy, and you want your rib cage to stay accustomed to its full range of movement.
Don't do heavy work if possible, especially not heavy work that involves lifting shit or bending over. Especially not bending your back.
This is a weird sounding one, but make sure you get regular gentle shoulder exercise. As the ribs heal they'll pull on all your torso muscles, and that'll lead to stiffness in your shoulders.
If they don't feel better after a few weeks, or if you get a fever or are coughing up mucus, go see a doctor. Even if chest infections are normal for you (as they are for me) you 100% do not want a chest infection while you have broken ribs.