Definitely stick with the raw and unsalted nuts and seeds as yoyoma says.
Salted nuts are too morish. And some seeds lose some of their nutrients when heated too much.
I would add another point. You don't have to try to shut down your whole usual way of eating overnight. But i find it best to try to tailor your own meal plans to the style of foods are used to eating. This probably only doesn't work if your diet is extremely unhealthy but it could be adapted still perhaps.
But i mean consider looking at the traditional foods in your region or from your culture too.
Are you able to cook at home? Are you interested in learning how to cook? I recommend it if you want to learn to eat healthy in the long term.