I don't understand anything of Zoho's API

I don't understand anything of Zoho's API

Hi , I have some things to do but first PSA : 
  1. I don't know anything about C#
  2. I don't know how to use Zoho API 
  3. I don't understand anything about it (Zoho API)
  4. I don't know how to generate token
The things I have to do is in C# : 
  1. Generate token 
  2. Connect to the api 
  3. Insert records into leads
  4. See the records into leads of the Zoho crm
Thanks for the explanation