I get it brother. You're looking in the mirror unhappy with what you see and you think to yourself: "Sigh, this is going to take forever to fix."
But I'm here to tell you its not. Just get your diet in order, start working out. Make it 2x a week to start, then move up to 3, then if you're ambitious move up more.
So in short to answer your question, the biggest tip is this: Get started and don't quit.