How to burn a .mp4 to DVD+R

There is a freeware software called Burn:

Made your own movies and want to share them with family and friends? No problem. Burn can create a wide range of video discs. From VideoCD to DVD-Video discs. And DivX discs to fit more of your videos on a disc.

I use it all the time for burning mp4s to DVDs, the finished product will also work with DVD Players too.

A lot of what you are trying to do depends on what you plan on doing with the resultant DVD. If you just want to play that file on a Mac than all you have to do is put it in a folder, right-click and select the option for burning the folder to disk (sorry, it's been a while since I did this and don't have a current Mac to reference at work for the exact procedure.)

However if you then want to play the DVD in a DVD player hooked up to a TV you may have issues with that. Look at the manual for the DVD player (or find it online) and see what disk formats it supports. Some do support movie files of various types burned to a CD or DVD (note that DVD+R is a newer format designed to avoid licensing the original [now called DVD-R] format and not all players play both kinds of discs.)

Also burning a DVD+R in the Finder will give you a Mac formatted disc that will not play on a PC and MAY not play on a DVD or Blu-Ray player. Check the specs on the DVD player for that as well.

If I need to burn an actual DVD (like you get movies and TV shows on commercially) I use Toast which can transcode the MP4 file into a format any standard DVD player will understand. I haven't done that in a number of years as I just play those files using Plex on a Mac Mini plugged into my TV.

Toast is a commercial product that you'll have to purchase. There may be shareware/freeware programs that do this but I don't know what they are.

Apple has removed iDVD from their suite. You will need to use a tool like iMovie (which is no longer free), or a 3rd party utility like burn