Let's talk about if a boy should be trained standing up or sitting down for potty training. I recommend that a boy learn to potty train by sitting on the potty. This is important because he needs to become comfortable on the potty because he will eventually have to sit on the potty to learn to poop in the potty. So it's important that your child be comfortable when sitting on the potty. Often times dads will ask me well you know when is he going to learn to stand and go pee in the potty, that's always dad's first concern and it's OK if your son in sitting on the potty and learning to pee because he really eventually learn to pee while standing up. Dad can teach him how to pee standing up or other boys at school can teach him how to pee standing up. It's actually best if he learns to pee while sitting on the potty and then once he's comfortable using the potty for both urine and bowel, then he can start to use the patty standing up.
One of the reasons I suggest that your son sits on the potty while learning potty training is so that he's comfortable when it's time for him to learn to go poop in the potty. You don't want him to learn to stand up in the potty to use the potty and then not know how to stand in the potty once it's time to go poop and you certainly don't want him to poop on the floor because that's going to be a huge mess and everybody is going to have to clean up, therefore you should teach your child to sit on the potty while learning potty training.