I arrived at the Ho Chi Minh city in the morning and checked in to a hotel in District 1. Most of the hotel check in time starts at 2pm local time, so plan your travel accordingly. District 1 is the central district and also known as Saigon. As per the local people, each district has its unique identity. District 1 is for party, District 3 is for sleep, District 4 was for gangsters in 70's, District 10 is for karaoke and so on.
In the evening visited, Bitexo Financial Tower skydeck at 49th floor. You need to buy tickets online or at ground floor. Each ticket costs around 250 VND. This skydeck has an amazing view of city at night. Try going there to view sunset in the evening.
Also visited 'World of Heineken' where they showed us about the history of Heineken brewing company. At end of tour they will gift you with a bottle of Heineken with your name printed on it as momento.
You can apply for Vietnam Visa on this official site: https://vietnamvisa.govt.vn/
You will get a visa approval letter in next 2-3days after you apply on this portal. You have to carry a hard copy of this visa approval letter and show it on the airport of Vietnam at visa on arrival counters also called 'Landing Visa' where you need to pay a cash of $25 . So please carry at least 25 USD hard cash with you.