It's between the Beach Club and Yacht Club resorts, but it's hidden behind the Stormalong Bay pool complex. Do NOT try to walk through the pool complex to get to it! (I suspect it can be done if you know exactly what you're doing, but Stormalong Bay is restricted to resort guests, and in any case it's not necessary.) Instead enter one of the resorts, and walk through interior corridors. Ask a CM in the lobby for directions if necessary.
B&C can be very busy at times, and the seating is very limited (34 table seats, and 15 counter stools). Early lunch or mid-afternoon are probably the best times to avoid a wait.