Kloudy
Welcome to the Forum,
I'm thinking Canary by the looks of it.
Does it sing at all, or just chirp?
Regarding the shape it's in, it looks a bit rough (might be moulting), but hopefully nothing that a good diet and good treatment won't fix.
I would offer a mixture of good quality Canary/Finch seed mixed together. A variety of fresh greens, some apple, hard boiled egg ( both white and yolk for Protein), crushed egg shell, cuttle bone and crushed oyster shell grit (for Calcium). Some bird vitamins, either in the water, or on the food.
I would also offer a daily bath of tepid water.
Some direct sunlight (as Andy mentioned above) is very good for them, but offer shade as well so that he/she doesn't overheat.
Let us know how things go on, and good luck.