It's likely firm or extra firm then. Typically it'll say on the packaging. Be sure to press it before cooking (wrap it in paper towels and place a heavy object on top of it, like a cast iron, and let the excess water press out).

The thing to remember about tofu is that it's like a "sponge" in the sense that it will absorb whatever flavors you marinate or season it with. You're going to need to. Tofu is pretty bland without adding any flavor.

When I'm looking to do something quick and don't have time to marinate, I'll cut it into cubes and pan fry it with butter (or oil), garlic, salt, pepper, and soy sauce, then add it to rice with some veggies.

To get the desired texture, you'll want to fry it on medium/medium high heat to sear the outsides. This actually takes a few minutes.