Create a Dropbox account if you don't already have one. Then upload a few sample photos to it.
Log into Pixl Now. Create a new book. Edit the book.
Click the top-left icon in the left panel. This is your page navigation. Then click + to add a page.
Click the fourth icon in the left panel. This takes you to your background library. Then click + to add a background image to the library.
Drag the background image from the left panel into the working canvas. That image should now fill the page.
Click the top-right icon in the left panel. This is where you create new objects. Add a new text object by clicking the letter icon. Make this the title of your page.
Try changing the font to Optima.
Click the third icon in the left panel. This will bring you to your photo library. Once again, click + to add images to the library.
Drag some images into the working canvas, and play with sizing, opacity, etc.
So there you have it, a single page created in no time at all!