Most cats will keep themselves very clean without a bath. Bathing your cat can help keep its coat clean but it is not essential. Some cats dislike being bathed so to help reduce anxiety it is a good idea to start getting them used to it at a young age. Try bathing your kitten in a shallow (about 10cm deep) bowl of warm water. Always test the temperature first and always use a pet approved shampoo. Do not get any shampoo or water in the eyes or ears.
When trimming nails, only the tip of the nail beyond the nail bed should be trimmed. It is best to get your vet or a vet nurse to show you the first time so you are confident in the future. Always trim from below the pad and use pet nail trimmers.
Longer haired cats will need regular grooming especially over spring and summer to help prevent dreaded matting of the coat and help your cat look their best.