The Castle Shop is on Krokosphinx Island. You may not have access to that yet.
There are two pet vendors in Krokotopia. The first is standing under an awning when you arrive on Krokotopia Island. He sells the Heckhound and Ice Salamander. A second pet shop is on the "secret" portal-to island. To get to that, you need to go to the portal between the shops at the Oasis and wait for it to activate. Be aware that this shopkeeper only sells one pet: the Krok. However, Tis'Mah, who's on the roof of the shop, offers to train Minion spells.
A long time ago, there was a third shop on another small island. However, this was taken out after beta testing finished.
The housing vendor and I think the pet vendor are on the island with the Krokosphinx. You have to complete the Pyramid of the Sun section main quests first to get access to the Krokosphinx. If you have a friend that has access there, you can always port to them. Good luck.
I have been trying to find the pet and house shops but I can't
i am assuming you are in krokatopia? if so, then when you get access to the krokosphinx, the vendors there will have the stuff you want. if i assumed wrong, then all of the house/ pet shops are with the rest of the shops
