Is this behavior normal/healthy in a snake? (New snake owner)

[Saika]

Hi guys, sorry but I don't know where or who else to ask. I just got a desert kingsnake a few days ago. He was extremely calm at the pet store and let me hold him. I took him home where I already had a terrarium set up with 2 hides, water, the hot side during the day is around 85-90 degrees and the cool side is about 75. It is a 40 gallon terrarium with lots of (fake) leaves and a fake cactus that he loves (lol...) I have a hygrometer as well and the humidity is around 40-60 at any given time depending on the day. I believe he is about 1 year old. He has clear eyes, no mites, healthy body.

However I am worried. He seems very calm... Which is great, but he seems so shy. Not a mean bone in his little body.I have left him alone for a few days and will fees him soon but at the sight of anyone he starts to slowly go backwards and hides. But he's very slow and relaxed even when hiding from someone. Is this normal? I've heard king snakes are usually aggressive. He has never bitten, threatened , or musked on anyone. When I change his water bowl he will stick his head out slightly from his hide and sniff and stay still, but I do not disturb him in his hide for now... Is this just how he is or is he not feeling well? Hes so gentle and shy that it worries me.