Adopt an older cat! There are way too many cats that are abandoned in shelters to be buying kittens from breeders.
You can syringe feed the kitten. For more information visit thecatsite.com/t/276288/3-week-old-kitten-not-gaining-weight
However the kitten acts and its personallity depends on what you should call it!
no
Instead of catching one, go adopt one.
You should take it to a vet!
you should call it kitty or....................
Get a kitten.
That is entirely up to you.
Ginger
The best milk for a kitten is their mother's milk. If the mother is absent, the best option is to find another nursing Queen that can take on a few extra kittens until they are weaned. As a last resort, kittens can be given Kitten Milk Replacer (KMR) which will need to be fed once an hour or every two hours around the clock. Never give a kitten cow's milk as this can make them seriously ill, and offers no nutrients to the kitten.
Go see a vet, the kitten probably has pneumonia or bronchiectasis.
This is not a good thing, and you should take your kitten to the vet immediately.