I have a 4 x 2 enclosure for the older guy, with humidity and temp gauges on each side, digital and regular. Temp and humidity are always good and attended to if one changes. Hide spots on each side, with water souce too. He is a happy little guy and loves to come out and play. Don't worry their environments are perfect for them i have been around reptiles for years.
Here's an article from a caresheet i found. --
Once you do get another snake you need to quarantine× it from your other snake(s) for a couple of months. The new snake may be diseased or parasitized and you wouldn't want it to infect your healthy animals. Once you quarantine, it's OK to put snakes in the same cage assuming: they are of the same species (Ball Python, Python regius), they are similar sized, and the cage provides ample room and hide boxes. I strongly caution against putting other types of snake together in the same cage. Other species snakes may have care requirements and different types of disease/infection that your Ball Python's immune system cannot handle. You will want to separate them at feeding time.
