1. Login to your WordPress admin.
2. Once you are logged in, go to Pages > All Pages and edit the page that you want add photo’s to.
3. Click the Add Media (displayed under the title) button to launch the media uploader interface, and then select the Create Gallery option from the list of actions in the left side of the media uploader window.
4. Upload or select your Images – You can then add or select the images you want in your page by uploading the images to use from your computer or by selecting from any previously uploaded images in the media library.
Once you have selected the images you want to add, You will see a checkbox next to the thumbnails confirming your selection. Then click Create a New Gallery.