If you mean your own artwork, then you'd take a picture of it, upload it to your computer (make sure you know where you're saving it), then select Insert > Picture in Word, browse in the location where you saved the photo, click the picture, and insert. If you mean an image from the internet or something, you can just save it to your computer and basically follow the rest of the steps above.
I'm seriously angry that Clipart is gone. Why? Because many of those cheesy images were available as Vector Graphics. So, I could quickly insert a crappy clipart into my powerpoints, ungroup the elements of it and delete all but what I wanted. I used it and it worked awesome for me multiple times. I wrote clipart off for years and only started doing this in the past 2 years...I wish I had known earlier.
If clip art appeals to you for its retro feel, you might also like pixel art. You can create some yourself with pixel art tools The 11 Best Pixel Art Tools to Create Pixel Perfect Artwork The 11 Best Pixel Art Tools to Create Pixel Perfect Artwork Do you want to try your hand at creating pixel perfect artwork? These pixel art tools will help you get started. Read More .
My school district doesn't allow students to access anything except Google; therefore, clipart is useless. More and more school districts and companies are blocking applications and websites to prevent access to inappropriate images and content. My first and second graders have always loved doing PowerPoints; however, with clipart no longer working, they cannot do these projects any longer. Older students access Google images to get graphics for their projects.