The hustle and bustle along the Venice boardwalk is a must-see for anyone who's never been to Los Angeles before. Rent a bike and ride down the boardwalk to see eclectic street performers, beautiful graffiti murals, hardcore people working out at the Muscle Beach Gym, and shopping that will suit whatever your tastes may be.
There's no one address, but you'll find the iconic Venice Beach sign at:
Pacific Ave & Windward Ave
Venice, CA 90291
There's ample parking all around Venice. You can find public lots owned by the city at 300 Ocean Front Walk, 2100 Ocean Front Walk, and 3100 Ocean Front Walk. Prices are $4–$18, depending on the season and when you arrive. There are also private lots to be found all over the place, but the city lots are typically cheaper.
If you're planning on renting a bike (or bringing your own), consider taking the Metro to the Downtown Santa Monica station. From there, you can walk to the beach and rent a bike for a quick ride down to Venice.