I have a Harvest Right, 5 tray “large” model. Instructions say you need a dedicated 20 amp circuit so figure that out first.
As for actual freeze drying, I recommend not overloading the trays. Do not mix frozen food with room temperature non-frozen food as some of it will be inconsistent.
Another tip, you can freeze dry anything. Frozen chicken livers made excellent treats for my dogs. You can freeze dry raw meat and stick it in a mylar bag and it will be shelf stable. Pretty crazy.
Happy to answer any specific questions.