Pet Care Needed - Full-time / Part-time

My 1. 5-year-old black Labrador is very happy, full of energy, friendly, but takes anything he sees and walks around with it in his mouth. He doesnt listen at all when we tell him to sit, lay down, put it down etc. we just want him to learn commands, and listen, if the door opens he would run out and not listen to come back. Please help!!