Ball pythons are naturally lonesome and sneaky creatures. They are also extremely curious and easily frightened.
So far, I agree with everyone else, Don't panic, if the snake was truly uncomfortable it would be moving around all the time flicking his tongue out and pushing up on the lid.
However, sometimes he may just be exploring his new home
If he stays in his hide all day that's PERFECTLY normal. They are nocturnal after all, Leave him alone for about a week and make sure to use VERY SLOW movements when handling him.
Hold him between two cupped hands (try not to over-handle) until he gets used to the handling.
Fast movements = Perceived Predator to a snake
Keep humidity around 50-60%, Make sure the tank does not allow for over-ventilation
You can buy some 3M tape strips for the back of the thermometer and stick it on the glass (near ground level) Just be aware that analog thermometers/hygrometers are not 100% correct. Get a digital if possible,
As long as he is eating, shedding, and hiding, he will be perfectly fine
Times when you SHOULD panic:
-Hear Constant Loud Wheezing (R.I.)
-See bubbles/snot in his nose/heat pits (R.I.)
-Stays inside water bowl for long periods (Mites or Overheating)
-Stargazing or Laying on Back (Stargazing, Inclusion Body Disease)
Check around the ball's stomach/abdomen and you will be able to clearly see if they are stressed or not based on how heavy they are breathing
(Their sides will move inwards and outwards at different speeds based on stress level)
Hope some of this info helps! as long as the tank temp is always above 75 and he has a hide, he will be fine!