new kitten....potty time help

HI! I recently received a new kitten. His name is Pepsi and he is about two months old and the sweetest thing ever. The problem I am having with him is that he pees on my covers and I have noticed that he has started to poo in a corner that is not very visible unless you move the couch, which I did and that is when I noticed it. I knew it was him because I had seen him run out of that corner a few times but I just thought he was being curious. I have 3 other cats, 2 grown ups and another 2 month old from a different litter. I have seen Pepsi using the litter box but he is not consistent. I am thinking that maybe he would prefer to have his own box. I don't know what to do. I am not by any means going to get rid of him I love him and we will get through this. Any idea of why he is doing this? And what could I do to help him stop doing this?
Thanks in advance.

He could be intiminated by the older cats. But I would advise you to keep him in one room with his own litter pan for awhile till he is using it 100%. And young kittens need a smaller litter pan to get and out of easier.

He doesn't really interact with the older cats he loves my dog lol but I understand what you are saying. Thanks for the reply.

He probably needs to stay mainly in some small room, preferable one without soft surfaces, with his own litter box. The other cats may be harassing him when he uses the box , and he'll look for some soft place (your covers or carpet) that feels good on his paws and isn't in use by the other cats.