Do I need to carry a lot of cash?

Carry enough for 3-4 days of expenses, but use ATMs to withdraw local currency as needed. Avoid money changers at airports if possible.

Is it safe to drink the tap water?

No. Never drink tap water. Use a filtered water bottle or buy bottled water from reputable convenience stores like 7-Eleven.

Planning Your First Backpacking Trip Through Southeast Asia

Focus your first trip on the 'Banana Pancake Trail'—Thailand, Laos, Vietnam, and Cambodia—to utilize established infrastructure. Budget for 45 days to cover the main loop comfortably without rushing, using a mix of budget guesthouses and sleeper buses.

Select your entry point. Fly into Bangkok, Thailand. It is the cheapest regional hub to reach from abroad and offers the most options for buying gear, getting local SIM cards, and meeting other travelers.
Map your route. Follow the classic loop: Bangkok -> Northern Thailand -> Northern Laos -> Northern/Central Vietnam -> Cambodia -> back to Bangkok. This avoids backtracking and maximizes your time.
Sort your visas before crossing. Research entry requirements for each country. Vietnam usually requires an E-visa applied for at least 7 days in advance. Thailand often allows visa-free entry for many nationalities, but check your specific passport rules.
Book your first two nights only. Don't over-plan. Book your first 48 hours of accommodation in Bangkok so you have a base while you adjust to the humidity and time zone. Everything else can be booked via apps like Agoda or Hostelworld a day or two in advance.

Do I need to carry a lot of cash?: Carry enough for 3-4 days of expenses, but use ATMs to withdraw local currency as needed. Avoid money changers at airports if possible.
Is it safe to drink the tap water?: No. Never drink tap water. Use a filtered water bottle or buy bottled water from reputable convenience stores like 7-Eleven.