Understanding the current King, his relationship with modern Thailand, and the context for royal reverence.
The current King (ascended 2016) is a different figure from his father — he spends significant time in Europe and has a complicated public image both inside and outside Thailand.
Lèse-majesté laws (Article 112) are among the strictest in the world — prosecutions have increased in recent years; foreign nationals have been charged.
Yellow and white flags on royal birthdays; the national anthem played at 8 AM and 6 PM at public venues; portraits in all public buildings, shops, and many homes.
Simply respectful behaviour is sufficient — no need to understand the politics; stand for the anthem, don't criticise the institution publicly, and you'll have no issues.