Its simple process. Just publish photoblogs or trips with good content and quality photos and then can earn credits based on the trips details and accuracy.
You can earn credits by publishing trip which consists of your itinerary, along with ther details like where did you go, number of days, where did you stay, the expenses.
then, there is photo blog- put up a picture and write about that picture
then, you can write review blogs as well. On basis of originality of content, you get the credits which helps you to travel on less expenses via tripoto travel packages