Hi Terry, welcome.
Try to stick to well known brands. They really are better. Supermarket flea treatment and wormers are not very good. For flea treatment try Frontline. Worming tablets, Drontal or Panacur which also comes in liquid form. These can all be found on sites on the internet much cheaper than elsewhere and you usually get the blurb telling you about the product and what age/size of cat it is good for. Do you know what your kittens have been eating up 'til now? It's not a good idea to suddenly change their diet as this can cause tummy upset. With this in mind, try feeding a mixture of dry and wet food. It should all be kitten food up until about a year old - the best you can afford. Water is essential at all times. With food it's usually a matter of trial and error to find out what they like, but remember to change over gradually. They usually wait until you've bought a stack of a certain food and then go off of it LOL Hope this helps.
Purrshah-persians
Sue