We can go back to the beginning but please DO NOT RATE until we are finished.
Your original question was how to delete pictures.
Launch the Gallery app from the Home screen or from the Apps menu (When viewing the screenshot, the following icons are available at the top of the screen, that is where the delete button is) when on the photo you want to delete, click the menu button and you should see delete there, then delete that picture.
As far as downloaded apps try the below again:
From a home screen, select Apps (located in the upper right).
From the All tab, select Settings.
Select Manage applications.
From the All tab, select an app.
Select OK. again.