From my subjective point of view, the rich people arrange their weddings in an expensive way in opposition to the budget couple. Of course, people also get married in churches and other public places as well. They celebrate their weddings in hotels and restaurants of different levels. Families with lots of money have their parties at high class restaurants or hotels, hire a nicely decorated bridal car for the bride and groom while budget couples celebrate at small restaurants or at home. Taking photos before the wedding is a custom that everyone follows, and lots of people go mad taking pictures by changing into so many different clothes and of course, they have to pay a fortune at the end.
Weddings in the countryside are totally different. Food is cooked by relatives of the bride and groom. Most of the foods are produced in their own gardens, from the poultry to the veggies. They serve their own home brewed rice wine, instead of beer. They serve specialities of the local region. Some dishes are weird and customs vary according to area. For example, in Thai Binh cat is served at weddings and in Ha Tay it's dog. It is said that dog should only be eaten at the end or in the middle of the month to release bad luck, and cat is good to eat early in the month to bring luck?
In Hanoi, if you wander around the photo studios, the Opera house, the rose garden behind Ho Chi Minh museum, or Reunification Park you'll see lots of couples waiting for their turn just for a few photos.