What things or points I should make sure of while mapping the properties ?

HubSpot properties have a specific field type such as:

– Single checkbox
– Date picker
– Number
– Single-line text
– HubSpot user

Therefore, the HubSpot properties can hold or store a specific type of value (for more information check Property field types in HubSpot knowledge base). 

So you have to make sure that the WordPress field being synced with the HubSpot property should be of the same nature.