I am new, how to use this website.

Have you read through the series of articles on the MFP Help pages? They explain many of the features and functions of the software application. You can also Search the MFP Help pages.

https://myfitnesspal.desk.com/customer/en/portal/topics/455841-general-questions-getting-started/articles

https://myfitnesspal.desk.com/customer/en/portal/topics/455840-food-diary-and-food-database/articles

https://myfitnesspal.desk.com/customer/en/portal/topics/455843-goals-check-in-and-progress/articles

https://myfitnesspal.desk.com/customer/en/portal/topics/455844-profile-friends-and-mail/articles

Also, please read through the pinned ("stickied") posts labeled as Announcements at the top of each Message Board in the Community Forum, especially the "Must Reads." You can also Search the Community Forum. Here are the two most important pinned posts to read through.

http://community.myfitnesspal.com/en/discussion/10300331/most-helpful-posts-getting-started-must-reads#latest

http://community.myfitnesspal.com/en/discussion/10300319/most-helpful-posts-general-diet-and-weight-loss-help-must-reads#latest