Most golf courses will allow non-golfers on the course but the conditions vary course-by-course. Some courses will levy a fee and others will insist that you take an extra caddie and buggy. We will advise at the time of booking and any charges must be paid direct to the golf course.
Non-golfers will be expected to dress appropriately and essentially follow the same dress code as the golfers themselves.
You can see details for each region of Thailand here:
More details on the dress code can be found here.