Exposure. If they don't already like snakes there's not much that is going to help, so that would need to be fixed. Otherwise, literally, it's a frozen mouse a week and the cleanup after for most species, heat pad on one end, clean water bowl on the other, and I shred paper as substrate.
As a first snake I'm not sure I'd suggest a rosy, as females tend to be chewy, some males off-and-on feeders, and you have to balance the desert conditions they need most of the time with higher humidity for shedding, plus there are some keepers who report them living 60+ years so it is a VERY long commitment. The gopher and rat snakes, or most of the kingsnakes, are somewhat more forgiving.