Modals of Obligation & Advice

What follows a modal verb: base verb or «to + verb»?

جرّب تحلّها أوّلًا ✍️

Obligation, prohibition, or advice? «You should drink more water.»

جرّب تحلّها أوّلًا ✍️

Choose: «You ___ (mustn't / don't have to) wear a uniform; jeans are fine.»

جرّب تحلّها أوّلًا ✍️

Write three safety instructions using must, mustn't and should.

جرّب تحلّها أوّلًا ✍️