How to get from Cambodia to Vietnam? Please give me some advice.

If you take a bus, you can go to Vietnam through Wuxing Pass, and from Wuxing Pass to Saigon, which is Ho Chi Minh City in southern Vietnam. It takes about 2 hours by car. If you want to have fun in Vietnam, you can play all the way from the south to the middle and then to the north.

If you fly, you can choose to fly from Phnom Penh to Hanoi, or Angkor (that is, Siem Reap) to Saigon or Hanoi.