We need to be able to tell people to do things in any language, and Latin is no different. In fact it has several ways of demanding action.
Most verbs in Latin have an imperative form and these should be learnt: cura! doce! curre! audi! for the four conjugations in the singular; curate! docete! currite! audite! for the four conjugations in the plural. You won’t often get that helpful exclamation mark in a Latin text, so it’s best to know the forms.
If you want to tell someone not to do something, then you can use a simple formula: put noli (singular) or nolite (plural) before an infinitive: noli timere, nolite ambulare. Another way of giving an order in Latin is the jussive subjunctive: a present subjunctive, on its own, is used with imperative force; for the negative version you add a ne: discet “Let her learn.” ambulemus “Let’s walk.” ne cantent “They should not sing.” Let or should are both good ways of putting a jussive subjunctive into English.