I am planning to backpack to Thailand and Myanmar in mid April. As it will be my first time for such backpacking travel I need your recommended places to stay, eat, and visit. And it is going to cheap travel for me. Thanks.
Your didn't specify destinations in each country. By guessing you might go to Bangkok and Yangon as a-must.
Songkran festival during April (13-15 Apr.) is the big event you shouldn't miss.
Spend 3-4 days in Bangkok around Khao San Road, plenty of attractions in the old town, cheap hostels and variety of food there. Songkran Fest on Khao San Rd. is the craziest in Bangkok.
If you don't want to stay in Bangkok during Songkran days, go to Chiang Mai, the centre of great Songkran. You need to do advance booking both transportation and accommodation. Throughout city will be crowded and full booked.
Bangkok and Chiang Mai have a lot of budget hostels in old town area from 200 - 500thb per night, just a few clicks on internet.
Street food also available, cheap and delicious from 35-60thb each meal.
Chiang Mai top attractions such as Wat Phra Singh, Wat Chedi Luang Worawihan and Wat Phrathat Doi Suthep, Chiang Mai Walking Street and outdoor activities outside city such as zip lining and trekking which you can book at tour agents around the old town.
Survival tip: For eating and searching any stuffs from ready-to-eat meals to a bottle of beer, basic medicine to sim card heading to 7-11 24-hour convenient stores. They are located every corner of Thailand.
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Koh Samui is the best! It is also central to other islands so it's easy to hop around for very little. Check out Chaweng that's a really fun place to back pack, especially for the younger traveler. :)