The easiest way is to fly! The Samui Airport (USM) has flights from Bangkok (BKK), Chiang Mai (CNX), Phuket (HKT), and Krabi (KBV). You can also get to Koh Samui from Singapore, Hong Kong, Malaysia, and China. We hope you can take our wedding as an opportunity to travel and explore Southeast Asia.
If you're a US citizen and do not plan on staying in Thailand for more than 30 days, you do not need a Visa.