Would you walk into a gym and load the bar with 500lbs of weight if you’ve worked in an office for the last ten years? Probably not – you’d start with 50lbs and work your way up over time.
Or you would get hurt.
Guns are no different. Start with smaller calibers or target rounds for your shotguns, and work your way up.
Or you could just ignore my advice and record yourself getting hurt and make all the other responsible gun owners look bad.