Illness/Sickness: Sick fire belly newts? help please

I am new to owning fire belly newts (chinese) and i recently purchased them about a week ago. i did a lot of research beforehand and i keep the temp of the tank a little chilly around 65-ish and i feed them bloodworms. one of them was a tad larger then the other when i purchased them and he doesnt like to swim a lot and he likes to sit out on rocks or stay still in the bottom of the cage mostly and i wondered if this was of any concern, he has also shed once already about two days ago and i assume ate it as it was no longer in the tank. just last night however it almost looked as though he was throwing something up. i also wanted to know if that was of any concern. i removed it from the cage as it was rather gross. i also have a second fire belly which i was worried about as when i bought him he swam around a lot but i noticed the next day he had a swollen leg and didnt use it very much and it recently progressed and looks as though it has sores on it. could this be from shipping? and should i do anything about it? i will attach pictures. however i apologize about some because the flash accidentally went off so the coloring isnt quite the same.

The one with the sore leg is likely to have an infection, in which case you´ll need to start salt treatments asap. It´s a very common problem with pet-shop animales because they are wild-caught, imported in terrible conditions and usually housed very poorly at the shops. As a result they are all extremely stressed and many develop infections. The infections eat away tissue, and can destroy whole limbs in a matter of days.

Other than that, you really should avoid using gravel. Not only it traps huuuuuuuuuuuuge amounts of debris but it can also be swallowed with dire consequences. Sand is a much better substrate, although you can also go without any substrate.
The water should be deeper. You need a minimum of 40l (about 10 gallons) of water, to ensure thermal stability, enough volume to buffer the accumulation of compounds, etc. You should also consider dding lots of live plants, these guys love them.

thankyou! and the tank is set up with the gravel only where the tank goes up on one side to get out of the water it has a fake plants on the far side not in the picture and i planned on adding real ones any suggestions? the tank is close to half or a third full how much should it be filled? i do partial water changes and try clean (remove leftover food etc) the gravel every couple days so that it stays as clean as possible. and how do you do the salt treatments and where can you get them

A picture of the full setup would be best if you would like advice on the setup. 6-8inches is a good depth for C.orientalis such as yours, but it could probably be more at the deep end if you wanted.
Perhaps have a read of the caresheet for your species:Caudata Culture Species Entry - Cynops orientalis - Chinese firebelly

How big is your smaller newt? It could be a juvenile, therefore it is likely to want to spend the majority of its time on land.

Salt bath information: Caudata Culture Articles - Salt Solutions in Treating Salamanders

thankyou for the salt bath information, and i will be changing the tank setup a little so i can make sure it is all clean before returning the newt with the sores. and the smaller newt is the one with the sores and is about the same length as the other but the other one has a lot bigger head and a larger stomach abdomen area which is why i was possibly worried about bloat because the larger one doesn't like to swim a lot but stays in a shallow area of the tank. but i am no as concerned with the larger newt as the skinnier because his sores have progressed on his leg but it doesnt seem to make him uncomfortable because he still swims and climbs around he just has trouble doing so because of his leg. I will put him in quarantine tank i have and i will post pictures of the new set up