Make the intention to pray. You do not need to say it out loud, but you will need to know which prayer of the day you are performing, what will be the type of the rakaat, and the number of rakaats. An example would be to think, « I will perform 2/4 rakaat/fard/sunnat/nafil of the Fajr/Zuhr/Asr/Maghrib/Isha/ prayer ». Remind yourself that you are praying to Allah alone and not show off or for the sake of another person (i.e parents).