HELP Mites or fleas?!?!?!

[Shu98]

I just got my syrian hamster few days ago and i give him kaytee's clean and cozy white bedding (i research online it was good)
But i dont know why it seems that most of the time i see him scratching it looks pretty rough and painful and im scared he has bugs on him or is it possible because he sleeps in his sand (where he pees and poop) sometimes??

Ive attatched a photo for u guys to help me!!! Thank u!!

[souffle]

Welcome.
His fur looks OK to me there. It's a but open but he looks to have a long coat and he isn't settled yet. How big is the wheel? It could be rubbing on his back if it is too small.
Check that and that it has not been oiled and is rubbing oil on the coat.
Hamsters do groom a lot. They are very clean but they also groom to spread their scent around especially after a cage clean or in a new home. You may see them rubbing their sides along the cage to spread scent from the hip glands.
Hard as it is try and not over clean the cage. You need to let him make it his with his scent in it. Use a cardboard box as a bed and not an enclosed plastic hut which might make him hot and stuffy. Baby hamsters take time to get a routine and learn how to nest and sometimes sleep in odd spots (like the potty) till they do!
Keep taming him but if he gets red or sore skin with obvious bites then see a vet. I would monitor him for now and keep up with taming so you can health check easily.

[Shu98]

Omg thank u so much!! Ill be sure to note about his fur and his cage