Yes, Thailand has surf! It usually doesn't get over head high, but some days are as good as anywhere. It's a great place to learn to surf. The Andaman coast is the most consistent, especially the Khao Lak area. Importantly, it's uncrowded, friendly and cheap! Khao Lak surf seasons:
Mar-Apr. - Shoulder season= small but good surf / good weather.
May-Oct. - Monsoon season= bigger surf / good and bad weather.
Nov-Dec. - Shoulder season= small but good surf / good weather.
Jan-Feb. - Dry season= very small surf / good weather.