Hola Irene

The form of the imperative for usted, ustedes, nosotros, in affirmative and negative, and also all subjects in the negative form coincide with the form of the present subjunctive. So, in this lesson, we are teaching how to conjugate regular verbs in the subjunctive and some of the examples you see, as you say, are commands. 

Here is a bit of information about this confusion about imperative, commands, present subjunctive

And also some lessons about forming the imperative in commands: 

Forming the imperative for usted/ustedes/nosotros/nosotras (affirmative and negative commands)

Forming the Spanish imperative of tú/ vosotros/vosotras (negative commands)

I hope they help.

Saludos

Inma