You’re using the new drag-and-drop interface. In the Camera drawer (as in your screenshot), you have the “photo from camera” block that will allow the user to take a photo and the “image from photo library” button that will allow the user to select a photo from a photo album on their device. That’s it. It’s also important to know that the second button does not currently work.
If you create a project and uncheck “use the new drag-and-drop interface,” you can then use the similar buttons from the legacy interface described here:
There is no “photo gallery” block in either interface. To create a photo gallery, you’d have to use a data viewer grid (Data Viewer Grid - ✕ Docs) or another method of manually creating a grid of images.