Wanting to know the best way to send data TCP UDP

My game is fully ready to accept connections via TCP and UDP and i can send data back and forth but i have a few questions on how i should package my data.

  1. What is the most reliable way to send a one time packet sending players information that consists of; Name, SessionID, IP
  2. Whats the best way to pack a movement request? in a array or some other means?