i need a pet with 90-100 intellegence but i dont know how to make that happen.
how do i boost thier intellegence?

You can boost a pet's stats simply by leveling them up, or by using Magic Food. Feeding a pet a Nutpea increases their Intelligence by a little bit, but you'd need a lot to make a significant difference. The best way is leveling. If you have a pet with GP, though, they have an automatic boost to all stats when they're born, so you won't need to level them as far to get to the required Intelligence level. 

how to i feed them magic food and where does it come from...store,trade?

you can find them by exploring the islands although they are hard to find. Also feeding your pet animal carbs whilst they are leveling will increase inteligence.

It helps to set your Diet Components to have all animal carbs selected. You do this by reducing other food stars.

If that makes any sense. Also, I cheat. I buy good used pets with GP 3 and high stats, and train them. Start building ridinghalls :)