Saving my iMovie to DVD
I have made a movie in iMovie and have tried the apps Burn and Express Burn and it acts like it's saving to the DVD but nothing is there. Burn is very straightforward but it still didn't work. I am using DVD+RW.
You probably just burned a data-DVD and not a DVD movie,
If you are trying to burn a DVD that plays in a home DVD player with menus and such, unless you have a very old Mac* and are *not* on Ventura, you will need a third party solution. Roxio Toast is often recommended.
I purposely keep some Macs running Mojave around so I can run iDVD.