A Muslim must reach puberty. Prayer is not compulsory for children.
Before praying, you must be clean from JANABAH (an Arabic term pointing to a state of ritual impurity caused by man and wife intercourse or by having a wet dream) in this case a Ghusl is needed (Ghusl is an Arabic term for the full-body shower with the intention (The Arabic word is NIYYAH) to make Ghusl)
A Muslim must make WUDU (not needed if Mualim just done Gusl). For detail, see the WUDU section
Standing in place of praying your face and body facing the direction of the Kabba in Mecca
Have the intention in your mind only what payer you are standing to perform.
