* Nānā iā ʻoe. (Look at you.)
* Nānā i kēlā. (Look at that.)
* E nānā i ka lani. (Look at the sky.)
There are other words that can be used depending on the specific meaning of "look":
* ʻIke (to see, to perceive)
* Hoʻolohe (to listen, to pay attention)
* Nānā aku (to gaze, to stare)
* Huli (to turn, to look around)
The specific word you choose will depend on the context of your sentence.