Gathering data from a database ( third party ) into the ZOHO CRM

Gathering data from a database ( third party ) into the ZOHO CRM

Dear community, 

If I want to transfer data from my database (Third party) to my Zoho CRM data base , how do I move forward with this ? 

Also if I want specific parameters from the database, i.e: Name, Surname etc.. of the users, do the API get them automatically or should they be coded into the API ? 

I am not an API expert at all but would love to know how it functions. 

Thank you for your time. 

Regards,