Can someone tell me if this bird is old or young
found in my garden not moving
Hi, it's not a recently fledged bird, but looks youngish. Assuming it is not injured, it might be suffering from an internal parasite, such as coccidiosis. This can be treated with a course of tablets.
Check www.helpwildlife.co.uk and see if they have a rescue centre near you. A vet will not take it, nor will the RSPCA.