How to Go About Changing Wallpaper on MacBook
Now that you're in the "Desktop & Screen Saver" section of System Preferences, options for changing wallpaper on MacBook are quite a bit more obvious. There are two buttons near the top if this screen. If the one that says "Screen Saver" is highlighted, click the "Desktop" button instead to get to the right screen.
Just below the two buttons is the image and name of your current desktop picture. Below that are two columns. The left column lists various sources for changing wallpaper on your MacBook. The right column displays the contents of whatever is selected in the left column, as thumbnails.
Many of these folders of wallpapers came with your MacBook by default, such as "Nature," "Plants," "Black & White," "Abstract," and my personal favorite, "Solid Colors." Hey, you get tired of being distracted by busy wallpapers after a while. There are shortcuts to your Pictures folder and your iPhoto library, and "Choose Folder..." allows you to change wallpaper from any image file on your MacBook.
Click through folders until you find the thumbnail for the image you'd like. To complete changing wallpaper on MacBook, click on the picture you'd like to replace the current one.