1) The main page shows recent activity on determined pins in which some can be similar in criteria of those that you have explored before or just randomly selected. You can refresh this page by clicking at the Pinterest icon.
2) when you click on the search icon it will appear some of your recent search, below these you can see the most searched words on Pinterest. Being in the results, on the top the page you will see some other suggestions of words you might like to used related to your search. That way the results page give you the option to add some words and take off others by clicking on the X of each word on the search bar.
3) At the news seccion you will simply find the notifications and messages from other piners.
4) At your profile page you can see your boards and manage them. At the very top right of the page you can find three icons, the plus sing that take you to make a new board, the second one is a search sing which you can use to search especific pins inside your different boards, the third icon is the settings one, there you can manage your profile, the account, find friend, etc. Then you find your name and your username next to a pin icon or your profile picture, by clicking on this one you can edit your profile, change your name, add your website and location, etc. Below your name and username you can find the total of pins you have on all your boards, the like you have give to other, the followers and the ones you have follow.
5) The buyable pins is the newest addiction to Pinterest ,where you can see the store that post that picture of the item and the price of it. If you want to get it just click in the blue button on the top of the page that says “buy it”.