Just to build upon what Tuvok has already said:
A 'standard' DVD (like the ones you buy in shops to watch your favourite movies) uses a special format, which is specifically designed to be used in DVD players (although PC drives can also read that format as well).
If you simply burn MP4 files onto a DVD, the vast majority of DVD players won't be able to play the disc; it will only play on a computer.
However (assuming that your computer has got a drive that will burn discs, rather than just read them) you can use a disc-burning program which converts your collection of MP4 files into the 'special' format which most regular DVD players use. The most popular program for doing so (and by far the simplest to use) is Ashampoo Burning Studio Free:
https://www.ashampoo.com/uk/gbp/pin/7110/burning-software/burning-studio-free
If you want to edit your MP4 files first, before burning them to DVD, VLC (which has already been linked to) can do basis tasks, such as cropping out unwanted sections of movies. For more advanced work, but without a steep learning curve, Videopad is an excellent choice
https://www.nchsoftware.com/videopad/
(If you really want to get into advanced video editing, see the options listed here
https://www.shopify.co.uk/blog/best-free-video-editing-software . Lightworks has been used to make several Hollywood blockbusters; it's superb but not for novices!)