Why is my puppy trying to bring something up without getting anything up?

How long has this been going on?

a couple of hours or more, my daughter said he did it last night as well, didn’t notice anything today

You need to take him to the vet ASAP.

Are you sure he hasn’t been drinking water or eating his food too fast?

I would call the vet, or the emergency vet, to be sure. If you are certain he has consumed something

Is he going to the bathroom, drinking and eating like normal?

He brought up some bile a while ago but nothing solid. Will call the Vet in AM again, only answering service Now 3AM.
All functions seem to be normal.

Yep, he probably needs to be seen tomorrow morning.

Good luck and I hope puppy feels better, soon!

Could be kennel cough, they hack and hack like they are trying to throw up but rarely do. Now you say it did throw up some bile so that makes you wonder. I would also say check to see if anything stuck in his teeth or throat, a twig or anything can cause that choking but again the bile doesn’t fit with that scenario. Did you take his temp? Should be around 101.5 to 102.5, color of gum and tongue should be pinkish. If you prod his gum with your thumb nail, will whiten and then turn pink again, check for dehydration by picking up loose skin, does it snap back? All things to check to decide how serious it is. Pups often eat stuff, throw up and then go on their way.