Home defense 12 Gauge ammo?

I would l like to know in the USA given how homes are made what is the best recommendation for home defense ammo. I have heard #4 buckshot? Is there different brass variants on the same #4 buck etc? I do not want over penetration living in a suburb and the home defense scenario would obviously be very close range and indoors. So penetration through walls or floors is not a desirable thing.

There are so many types of ammo and being new to shotguns it can get confusing. There is also allot of different opinions.

Thanks for any input.

• On a side note what would be a good ammo to use on a range just to practice and get used to. I will use various obviously depending but I was thinking just as a cheap staple ammo that is not too light to be pointless and not too heavy to be excessive like a 3” slug. Basically to run the new gun in.