Having been to Thailand, Cambodia, Bali several times and as recent as a month back - her are some suggestions (I'm assuming you live in the US):
Bangkok (BKK) - Try staying at a US chain of hotels in BKK - and you wont have any surprises. My favorites are in the Ploenchit and Silom areas - and you can get reasonable prices at Agoda.com. Also consider staying at a service apartment such as the Centerpoint chain - good value for money. I never pay more than US$70-$80/night including breakfast for a 4 or 5 star property. The Thai hotels are cheaper but you can get surprises if you stay in the Nana area or around Soi 4 Patpong. Food is a plenty but stay away from raw food and bottled water is a must.
Transport by BTS (Skytrain) or the underground is easy to use; and Uber is also becoming popular. If you rent a taxi be sure the driver uses his meter.
Tourist areas include the Sleeping Buddha, the Wat Pho, the night markets etc - take an unlocked phone and get a prepaid SIM at the MBK market for 300 BHT (approx US$8) you will get free calls and unlimited 4G for 15 days. Calls/text messages to the US are cheaper than domestic calls
Tours are a plenty but stay away from deals in the Jewelry district or tour /massage/soapy packages from Tuk-Tuk drivers..They usually take you to dives and you will be disappointed. Visit the Royal Palace, the Sleeping Buddha and the night markets. Go to the Lamlukka area (BKK suburb) and get an authentic massage at the temple - cheap and awesome.
Consider taking an overnight trip to Pattaya Beach - lot of sleaze in Boy's Town.
Local gay action - check out dreadedneds.com - an excellent resort of what and where to visit for "gay fun" in Bangkok or Pattaya.
Travel to Cambodia - go through Bangkok or Singapore - 2 days is what you will need in Siem Reap. Be sure to take a bunch of $20 bills - a visa is available on arrival at the airport ($20) and 2 photos Be sure to see the Angkor Wat at daybreak and at dusk. My favorite place to stay is the Raflles hotel . An all day taxi will cost you $45-50.
Great gay action in downtown Siem Reap too.
Need more information - PM me
Rick