The standard video program that comes with Windows 10 does not play DVDs. You will need to download a 3rd party player in order to play DVDs.
You can use the Windows Store and search for/download VLC. It does a great job and is constantly being improved/updated by the author, so you have ongoing support.
If you would rather have a desktop app, VLC for desktop is unsurpassed in features and usability. Visit the videolan.org website to get it.
Best of all, it's a free solution.