My budgie is stting on a perch with puffed feathers?

This is common for my green cheek conure as well.
It usually depends on the temperature of the room. If you have a tropical parrot, I recommend keeping the temperature fairly warm in the winter.
This could also mean that your parrot is just very tired. If he continues to fluff his/her feathers, try playing with him less often. (If you play with him more frequently.)
If you follow both of these instructions, and nothing happens, you may want to take him/her to a vet.

if you just got him from the petstore and you already have him out in your room hes probably scared, most birds need a few days to settle down before they feel comfortable in a new environment.

Your bird is just uncomfortable, try to allow him 48 hours to adjust to you and the new cage, just spend time near the cage and keep speaking softly to comfort your new bird.

Your budgie needs some heat .

Sounds like he may be cold!