Hello Phillip
temperature is what your comfortable with 70-80 degrees Fahrenheit
lifespan is usually one or two seasons [1-2 years]
Humidity on juvies needs to be a bit higher than adults to aid in shedding.
Holding is OK for some species but remember males can and will take flight so do your holding indoors, females tend to get to heavy after a few meals when adults.
Mealworms are not a great food source, a varied diet is best and feed it as much as it will eat.
Juvies and babies will take smaller food items such as fruit flies or pinhead crickets [don't know what you have available on the other side of the pond
]
Keeping just one per enclosure is perfect.
good luck