This app

It took me some time too ! Its tricky at first like any new app but in no time at all , you will have it all figured out ! It took me a few weeks at first and then I had it all figured out.
If you need help or have a specific question, please feel free to create a thread here. Plenty of knowledgeable members will try to help !
Best of luck to you !

Have you taken a look at the getting started posts pinned to the tops of each forum category? If not, you'll find loads of information there.

I'd suggest starting here:

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