Where Are My iPhoto Photos Stored On My Hard Drive?
To find iPhoto photos on your MacBook Pro 13, double-click the Macintosh HD icon on your desktop, click on the Users folder, click on your folder within the Users folder, then click on Pictures (or from your desktop, click on the Go menu, then click Home, then click on Pictures).
Within the Pictures folder there should be a file called iPhoto Library. Right-click or hold the Control key while clicking on iPhoto Library and select Show Package Contents. This will display various iPhoto related files as well as all of your photos.
If you are looking for specific photos, navigate to the Originals folder. Photos are organized by date.
If you have the newer version of iPhoto called Photos launched in 2015, you can find the photos using a similar method except instead of looking for iPhoto Library it's named Photo Library. You can then click on Masters to see your photos grouped in folders by year.