Hello onbin,
Welcome to Communities.
Just so you are aware, this is an English-language forum and thus I would advise you put questions in Google translate or similar before posting - or ask in the Chinese-language sub-forum:
VMTN Global Forums
"For example, should vSphere purchase the standard version and the enterprise version? Does vCenter require a standard or enterprise version? What kind of license does the vSAN feature need to buy?"
You can use any vSphere licensing level with vSAN - vSAN requires its own licenses in addition to these.
"If you need to purchase additional licenses in order to implement some of the more important features?"
Which vSAN licensing level you require depends on the features you require.
This guide covers all of this:
https://www.vmware.com/content/dam/digitalmarketing/vmware/en/pdf/products/vsan/vmware-vsan-67-licen...
Bob