Wudu is the washing Allah commands before prayer in Quran 5:6, and the Prophet (peace be upon him) taught it by action. In order: make intention in the heart, say Bismillah, wash your hands, rinse your mouth and nose, wash your face, wash each arm up to and including the elbows (right then left), wipe your wet hands over your head and wipe the ears, then wash each foot up to and including the ankles (right then left). 'Uthman (may Allah be pleased with him) demonstrated exactly this and said he saw the Prophet perform wudu the same way; your wudu stays valid until it is broken (for example by using the toilet or passing wind), after which you renew it.
Evidence — the daleel
On deen2u
Informational, not a personal fatwa. Consult a qualified scholar for rulings on your situation.