Learn Spanish (Latin America): El estudiante mira el mapa.

No, the word estudiante stays exactly the same for both men and women. To show that a student is female, you just change the word for "the" from el to la, making it la estudiante.

Where is the word for "at" in this sentence?

The Spanish verb mirar means "to look at" all by itself. You don't need to add an extra word for "at" because that meaning is already built right into mira.

Could we just say Mira el mapa without El estudiante?

Yes! If we already know who we are talking about, we can drop El estudiante and just say Mira el mapa, which means "He looks at the map" or "She looks at the map".