to be honest, it doesn’t matter. If you’re on a budget then get a used nikon D7000 series or a D610. Just make sure the shutter count isn’t too high. Under 50k is best. Over 100k is too much. The lens is more important than the camera body. You’ll keep them for years. A 50mm 1.8 lens is good to start with, and can be had for cheap.
If you have money, then you can get new camera. Any brand is good. Just depends on what you feel most comfortable with. Mirrorless bodies are nice, but I haven’t upgraded yet.
You don’t need top of the line equipment to make money in photography. But you’ll want to have a flash or two so you can do indoor shoots/events and add pop to your outdoor shoots.
Your eye for taking good photos and your ability to get people to book and pay you, is what will make you successful. I’ve spent more on education than I have on gear.