I will need to play on the Church's laptop. I have been advised to make sure I movie is in MPEG4 or AVI, but not sure how to do that with a Mac 10.13.4 High Sierra?VLC should be able to play it on PC without any conversion.
Depending on the windows version you have, the default media player might be able to also.
I was told that it needed to be in a MPEG or AVI format. (I don't know what kind of program the laptop have on it.)MP4 and AVI are just containers. Have you tried to play the video on the church's computer and failed or are you just assuming it won't work? Most MP4's will or should play.