changing background

I recorded my grandchildren singing something in a basement bedroom that had white walls. Is there a way to put a nice jpeg picture in the background to replace the white walls?

The quick answer is "yes" it's called creating a composite. However since you're asking the question it means you don't know what it is, (similar to a "greenscreen" shoot setup) and you'll find trying to accomplish it will be a painful and long process that will make you want to pull your hair out.

If it's a must-have and can't live without a different background I'd hire an experienced editor to do it for you. If it's just for fun I'd let this one go.

Thanks for an honest answer. I will let this one go.

Is it easier to add a green screen? If so -- how?

You don't so much 'add' a green screen. You film your subject in front of one.

Kinda late in your case.

Thanks for your response. I know it is too late for what I have filmed in the past. So moving forward, where can I find out how to add a green screen. I know my former school had a large green wall they used for a green screen, but I think there is a way to add that on my computer. If I transfer videos (MP4) and photos (JPEG) from my canon camera to my computer, can I put them on a green screen or how does that work?

For photos, you can cut them out by hand in Photoshop or similar software.

But for video, you need to shoot your subject in front of a green screen or you are looking at very tedious frame-by-frame work with the help of expensive software like Mocha or Silhouette (or getting mad without one) in a process which is called rotoscoping.

how to add a green screen.

You buy one, set it up, and light it properly.

https://www.bhphotovideo.com/c/search?q ... unds_23716

That's the short version, and then there are hundreds of videos on YT…

If you have the Studio version you could try the new Magic Mask. If this works on your clip you could easily change the background. How good the result would be is anybody's guess. Just google Magic Mask to find youtube examples on this.

Google "davinci magic mask change background"

I'm sorry to put some water with the wine, but IMHO the Magic Mask will not cut it (pun intended).
It's great to make a soft mask on people for grading, but it is far from what a green screen can do.