Your cat should be using their litter box, so your priority is to train your young kit to use this space properly. Generally, it is not a good idea to use puppy pads for training kittens or cats to go to the toilet. However, they can be a good back up if you have a poorly, elderly, or immobile cat.
If you do want to use training pads for your kitten, there are cat specific pee pads on the market.