We recommend odd numbers, because there is a saying in China: Misfortunes never come singly, but good things come in pairs. Choosing a cemetery is a trivial matter. People hope that there will be fewer such things, so it is recommended to choose an odd number.
For some knowledge about funerals, you can search Baidu's "Zhengzhou Baishi Tong", which contains a lot of common sense and knowledge about funerals that you can learn from.