Before you sharpen, create a new top layer that combines the layers below. Type these two keyboard commands, in order: Ctrl (Command on a Mac) +Shift + C, Ctrl (Command) + Shift + V. If you’ve set up Photoshop to show the proper print size, go to View > Print Size to sharpen for print. Then go to Filter > Sharpen > Smart Sharpen. Resize the window if necessary. Then check Preview to compare how your image will look at print size versus close up. This image has little noise, so you can get away with a high Amount setting, a low Radius setting, and just a bit of noise reduction.