Is Mirissa or Weligama better for a first time surf lesson?

Weligama is significantly better for absolute beginners. The bay is huge with a sandy bottom and long, gentle waves that are perfect for learning. Mirissa has a reef break which is more suited for intermediate surfers. Most surf schools in Mirissa will actually drive you to Weligama for your first lesson anyway. The water at Weligama is also waist deep for a long way out, making it very safe.