Absolutely! Thailand's islands and vibrant capital city are exciting places to explore. Here's what you need to know:

Best Time to Visit:
Phuket, Rayong, Pattaya, and Bangkok are incredible destinations all year round, but November till April are ideal as these months receive the least rainfall. The climate during these months is cooler and relatively drier.

Route and Accessibility:
Bangkok, the capital city, is well connected by air to major cities around the world. For intercity travel, domestic flights, buses, taxis, and boats are available. From Bangkok, you can take a flight or bus to Phuket, and for Rayong and Pattaya, private cabs, buses or minivans are available.

Altitude and Acclimatization:
These destinations are near sea level, so altitude sickness doesn't apply here. However, adapting to the tropical climate takes a bit of time - stay hydrated and wear loose, comfortable clothing. 

Accommodation and Booking:
You can find a range of accommodations for different budgets in all four cities. For Peak months, it is advisable to book in advance. Online booking sites offer good deals and options.

Clothing and Essentials:
Packing should include beachwear, flip-flops, and light, breathable clothing due to the tropical climate. Sunscreen, hats, and sunglasses are essential. Formal or semi-formal attire could be required in higher-end establishments in Bangkok.

Health and Safety:
Tap water isn't safe to drink; always opt for bottled water. Mosquito repellent can help prevent any mosquito-borne diseases. It's also prudent to have travel insurance due to the adventure activities prevalent, especially in Phuket.

Local Etiquette and Respect:
Thai people have deep respect for monarchy and religion. Hence, one should dress modestly while visiting temples. It's considered impolite to touch anyone's head or point your feet towards people or religious artefacts. Remember to keep a smile on your face, as it's an important part of Thai communication!