Thnx for the tips bro. Indeed I met and chatted with so many fellow tourists and locals when I was in Saigon! Don't mind if I ask, how long is your trip to Vietnam? What are your routes were? Also how much did you budgeted for your trip? I'm planning a 1 month solo backpacking trip south to North next feb/march/April so I'm scouting for things to do and places to visit
I initially planned 2.5 weeks for $700 but I overspent at the start, right now, I will stay for 4 weeks, targeting about $1100 excluding flights.
I did Hanoi-Sapa-Halong-Hue-Hoi An-Danang. Going to Mui Ne and Dalat next, currently in Saigon.
Should definitely go to Phuong Nha if you have money. Heard Nha Trang is cramped with Russians so I'm skipping that. Might go to Vung Tau and Phu Quoc.
Anyway, my advice to you is - don't have an itinerary, just bring a guidebook and tripadvisor. Bring your ATM card. You will meet people and see tours that you want to do and by then, you would appreciate the flexibility in your plans.
Also, travelling alone is more expensive than in pairs. You pay slightly more for a better dorm compared to a double room. Taxi rides are expensive. You don't have a 2nd opinion so will definitely get ripped off (angmohs dont count cause they have no sense of pricing around this region)