Please Answer?

Assuming you will be keeping the dog inside while you are away at school/work, the simplest thing to do is crate train the dog, and also train it to only relieve itself every 4 hours. If you buy from a reputable breeder, the dog should already know how to do these two things. As mentioned by someone else, dogs get lonely, so I would consider getting two dogs. And, I am a huge rescue advocate; I would check the local shelter or rescue groups. In the US we have breed-specific rescues. Good luck!

your house MUST have a good fence that it can not get through any gaps and that another dog can not get in through
you need to put in a doggie door flap so it can go in and out when it needs to... or you invest in a super deluxe dog house outside for when nobody is home... really king charles cavalier are lap dogs that do not like being alone so you will really have a problem

Feed the dog on a schedule. You will know when she needs to go. If it is a puppy, it is going to take a while before it has true bladder control. I've heard of people training small dogs to use a cat box. Could work. But she has to know where to go if she has to go.

When the dog is young, it will suffer separation anxiety. Try to work your schedules so that the family takes turns being with the dog. Some people take a week or two vacation time so they can be home to help the dog adjust. During that time, start experimenting with short separations. Only a few minutes. The dog will soon understand that you will come back. Some people use crates. Personally, I like to have a room, like a kitchen or bathroom that I can leave the door open and put up a gate. That way the dog does not feel trapped.

Provide plenty of toys. Some people play a radio or even leave the television on to help the dog be comfortable.

As said "Unless mum is in agreement with this idea, you are on a hiding to nothing. Mum is quite right too - she's out at work and you are at school. What then for a puppy who needs somebody around most of the time at first, if just to get housetraining done. No adult dog should be left alone at home for more than 4 hours without the ability to empty either."

nd no puppy should be left alone at home for more than a couple of hours or you'll just come home to a huge mess. Physically puppies can't hold for much over 2 hours. As for having the ability to get outside when nobody is home - forget it. Not only will he make a load of noise and upset any neighbours within hearing distance, bringing them to your door, but word gets round when dogs are left alone for hours, especially purebred puppies, and they will be stolen. Perhaps 'to order' and perhaps to use as fighting bait. The puppy /adult MUST be safely indoors when nobody is at home.