There's a couple ways to say 'cool' in Spanish. My favorites are 'chevere', you can also say 'bacano', or you can just say 'fresco'.
If you want to say something like 'that's a cool shirt', you could say, "Que camisa tan chevere." Let's try that: Que camisa tan chevere. If you want to use some of the other words we learned, you can say, "Que camisa tan bacana."
These are all different ways to say 'cool' in Spanish: Chevere, bacano; or if it's a 'camisa' 'bacana', or fresco. Que camisa tan fresca; what a cool shirt. These are all different ways to say 'cool' in Spanish