To get started with travel start you need to register with them first in order to get affiliate account 
which can be registered from here :
And then click on " Sign Up Now

complete the registeration form and wait for approval, generally travelstart takes 2 - 3 business days to approve your affiliate account and get back to your with required credentials which you need to use with our application. 

after you receive the email from travelstart for approval it should contain a attachement of txt file which have a code of iframe for your affiliate account it should looks like below image : 

Copy the Iframe ID and AffID codes and paste into travelstart module settings page see below 


that is all to setup the Travelstart, for menu on main navigation and change the position manage it from CMS Menus 
for payments and affiliate % Commission related queries please contact travelstart so they will guide you better.