dont have money now for vet, just wanted to know– i love my pets

There is a stray kitten outside that I give food. Well I recently realized that this kitten has worms. I can’t keep him, only because I have 3 cats and 1 dog and my husband doesn’t want anymore pets. But he doesn’t mind me feeding him. He tells me to get him some worm medicine, which I intend on doing but my only concern is, If he is an outdoor cat and is constantly around other stray cats, won’t the worms eventually come back. I figure eventually I can convince my husband to let me keep Gizmo (that’s what I call him) but in the mean time what should I do to keep the worms away. I know fleas are the cause of worms, but Giz is to young for the drops. What should I do.
I live in Southern California.

my dog is a yellow lab 4 months old. he has an ear infection and we are taking care of that. but about a month ago he started dry heaving, first i thought it was just the pool we got him, to much water in take, even the vet said that. but yesterday he dry heaved when he woke up. and that seems to be the only time he dry heaves is when he wakes up from either a nap or sleeping. he eats stuff outside, grass, kumquats, dirt. im just wondering if anything he digested could be the problem, could he have caught something because of it. he has all of his puppy shots, he got his heart worm medicine last month on the 25th. the vet says hes fine. he is normal during the day, he is crazy as hell, he loves playing, he doesnt seem like something is wrong with him. but im still kind of wondering why he dry heaves when he wakes up, can anyone answer my question.

Over the past week my dog has thrown up several times. I kept an eye on it, but it was mostly food so I figured I would try to slow down his eating or give him a little less food. I found a round worm in his poop yesterday so brought him to the vet. They gave me 2 doses of medicine to give him, one for right away, the other for in two weeks. He threw up the second I gave him the first dose. They said to wait 15 minutes and try the second dose. Same thing happened. I called them and we made an appointment for this morning, which they checked him and said we’d just try giving him the medication again. As soon as I gave it to him he threw up again. He is not throwing up any round worms, so the vet seems think that vomiting is from something else.
He is eating ice chips and keeping them down but that’s it. Last night we gave him water and he threw that up.
What is going on???
(I’m waiting for the vet to call back but would like different opinions).
Thank you.
He is not having diarrhea and there is not much in his vomit except partially digested food. I see no worms at all.
I called another vet this morning and they said they would have done the same thing.
I just called a different vet and they said to give him hamburg and rice to see how he does and call my vet and ask if they have another form of the medication. She said the vomiting sounds unrelated to the round worms.
I’m so worried that it is parvo.

i wanted to know if there is any posibility that i can get it too.