Mommy to 2 twin fur babies

🐝-zz off!
I understand this is a relevant but I am so confused and I need help. I have never been a cat person and have two kittens I have adopted. They are about five months old cause and both males. They have no problem using the litter box are eating. Yesterday I change the litter box and it smelled like pour ammonia which could be a sign of a UTI or dehydration. I plan on taking them to the vet soon however, my main concern now is, I've noticed they don't drink enough water. I've tried, even "force feeding" them water, they won't even drink water from any bowls I leave out. Any advice for first time kitty mama? 🙀