FYI: THIS IS JUST INFO ON FINDING QUALITY PICTURES.
YOU DON'T NEED TO DO ANYTHING ON THIS PAGE!
Using Google photos, search for good quality photos (not cartoon/clip art or logos). Check the dimensions - they should be at least width 400 pixels!
Before you copy the picture, make sure it's big enough. Your photo should be at least 450 pixels wide so that it's clear in the PPT. If it's only 250 pixels, then you'll probably be making it bigger in the slide and it'll be blurry.
Don't copy the thumbnail! You need click on the thumbnail and then copy the picture at full-size. Make sure the full-size picture is good quality, clear/focused, not blurry!
Right-click on the full-size picture and choose "Copy Image". Then in PPT, click anywhere on the slide (so long as you have text in your text boxes) and paste (CTRL+V).
When you bring in a really big picture, you'll need to make it smaller in PPT.
Option #1: Right-click on the picture, go to Size & Position.
... and change the % for the height and Enter.
Option #2: Hold CTRL and drag the scroll wheel on your mouse in/out until you can see the whole picture. Drag it in from a corner until it's on the slide, then scroll out to see the slide at a normal size again.
If you've put in a lot of big pictures, you'll want to compress your photos so your PPT file size doesn't get huge (and slow down or crash PPT when you're working on it).
Click on the picture, then go to Format tab. Click on Compress Pictures...
To apply to all pictures, uncheck the box for "Apply only to this picture". Use document resolution.
If you have a picture that needs to be behind other pictures, right-click on it and "Send to Back".
In my example you can see it's now tucked behind the title.