yes its sick. make sure it really is a wild bird. it might be someone elses lost bird maybe. if you are 100% sure its a wild bird (like a crow or blue jay or something) then you should call some wild animal rescue people (whatever its called).

give him some clean water to drink

Earlier today I found a bird on my porch who didn't seem to be afraid at all of me even when I sat down right next to it. I tried giving it some bread but it just stared at me and chirped so I just left it be. But later in the afternoon I saw it in the same spot just sitting there but now all puffed up?

The bird won't leave even if I touch it, is the bird ill or something?