This videos are awesome on phase information and what phase is, especially if you have the ability to use open sound meter (free) or SMAART ($500-$1000) or the JL Audio Max. There are other softwares that can do it, those are just the most popular that I know of.
Set aside a couple hours to watch these, they are well worth it! Nick does an AMAZING job at breaking these things down!
https://youtu.be/NrJxJABjJOw
https://www.youtube.com/watch?v=FpbqAJpCKGg
JL has actually been putting out some really good how to videos the past couple of months
https://www.youtube.com/c/JLAudioInc/videos