I would recommend avocado oil for cooking, and olive oil for salads etc. Avocado oil has a much higher smoke point, so it makes for easier cooking and fewer carcinogens.
Olive oil is fine for cooking as long as you're constantly moving it (e.g. sauté, stir fry, etc), because then it never gets a chance to really heat up beyond its smoke point. It's not great for deep frying or foods that you leave in the pan, like steak or seared fish (unless you get refined olive oil, but then what's the point?).
That said, I second the recommendation for avocado oil for general cooking.
