Behavior I think my guinea pig is not feeling well

No, you should worry, and you should get him to an exotic vet ASAP (don't bother with a dog-and-cat vet if you can possibly find an exotic one). A guinea pig that isn't eating is in real trouble. Sounds like he has an upper respiratory infection, and those need prompt treatment. It's nothing you can treat yourself -- he needs antibiotics, and he needs them quickly.

He also needs to be hand feed. See https://www.guinealynx.info/handfeeding.html for instructions on how to do that. If you can get the syringes you need tonight, you can make a slurry out of crushed pellets and water and use that until you can get to the vet to get something like Critical Care.

Guinea pigs hide illnesses very well. You'll have to pay close attention and get help for him at the first sign of any illness. Sometimes by the time you notice something is wrong, they're too far gone to be able to help them. I hope that's not the case with your pig. Good luck with him, and let us know how he gets along.

We'll I can't get him to a vet tonight my parents are asleep and my vet is closed at night what about tomorrow morning?

Keep a close watch on him and do what you can to encourage him eating. The sneezing and sleeping sound alot like how my girls were 4 months ago. They would sneeze often and seemed to sleep more. Most clinics close on normal hours but there are some exotic animal hospitals that are open 24 hours. If you can't take him tonight, then as soon as possible, via tomorrow morning. I will pray for your piggy!

We'll he is eating now so I think he is fine I think he was just full so I think he is fine thank you for helping me.

Normally, and from my understanding Guinea Pigs don't overeat but you can't be too careful. Sleeping alot, or all day is a sign that your piggy may be sick. Like @bpatters said post updates and keep a close watch. Check his nose for discharged, or excessive fluid as that is also a sign of URI/Infection. My girls had a light hint of URI but I took them to the vet ASAP to get it taken care of. Also check his breathing and poop. https://www.guinealynx.info/uri.html <-- Great information. I usually cuddle and listen in if I can to hear their breathing. "Clicking" sounds result in a possible problem. Watch for the symptoms listed in that link.

geminigp said:

We'll he is eating now so I think he is fine I think he was just full so I think he is fine thank you for helping me.

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Guinea pigs don't get "full". They eat and eat and eat. Their gut is constantly on the move. You should get a needless syringe for when he ever stops eating again. You can make a "pellet smoothie" and force feed him with the syringe. Force feeding pigs when they stop eating is part of what saves them when they are sick. It sounds like he has a URI.

Honestly, I would still take him to an exotic vet to just give him the once over. Guinea pigs are prey animals and hide their illnesses well until it's too late. As a former exotic vet tech, please please take your guinea pig to the vet. In my opinion, it is always better safe than sorry.

To put it in terms that are a bit easier to understand, have you ever been really sick, then suddenly felt okay? You got up, made something to eat, and then because your body was still in 'repair and rest' mode, you crashed and where worse than before? Even chemotherapy patients will have good days and not feel horrendous; it doesn't mean they aren't still sick. It would be best to get him checked out, regardless of whether or not he's eating again.