he's a jack russell terrier and is about 3 months old and i just bought him yesterday, he was fine and energetic at the pet shop but now he's down and sad and wont' eat, he keeps sneezing, his eyes are red and he won't eat nothing, only drink water he's shakeing too and i called the vet but they are closed :'( for the mean time how can i make him feel better and relaxed, i feed him 2x a day wake up to walk him give him his rest, take him 2 go poppy outside , any help? thanks!
oh god thats horrible i will do all u guys suggested i dont want him to die

Often times when puppies come from pet stores or back yard breeders they have kennel cough. This needs antibiotics and is contagious. It could also be a variety of other things. Many places have a 24 hour emergency vet hospital. You should check your phone book and see what you can find. If none available, get him to the vet first thing on Monday morning.