Vietnam for 2 weeks. What are your favorite parts?

Hi there!

I'm flying to Vietnam late this September into early October for roughly 2 weeks and wanted to get recommendations for where to visit.

For the record I'm a 22 year old Canadian and Id like to explore/hike the country side but also meet others backpackers over a few drinks or just hang out.

My plan is to fly into HCMC and visit a friend for a couple nights then head to Dalat then head up North to Hoi An area then Hanoi for a couple nights, get to Sapa for a few days then Ha Long Bay then back to Hanoi.

Any thoughts?