Recording to test right and left channels...

OP,

you did not mention LP, just how to know if left right is correct.

Done?

elliottbnewcombjr the example tracks are available on all formats:
 "Take Five by Dave Brubeck".
 Adele track "send my love"

And then there is LP calibrations/reference test discs. But I find Adele to be preferable.
But LP test discs is better in other areas than just know what is left or right channel.. 🤔

PS Audio has a great CD/ files with an accompanying book. Check out their Octave Records section. In includes phase checks and much more. Comes as SACD/CD with or without book. 
Based on your question, this would be a great way to educate yourself and tune up your system. 

Second that.
The disc from ps audio has something that is little bit unusual. There is tracks were the performer is recorded and documented with different distances with further and further away from the microphone.

That is great because 99.5% of the time we have no information of what distance a artist/instrument is from the microphone. And can be good to train and to be able to hear the differences.

Yeah you can hear if it is mounted in a acustic guitar body (no room information) or if in some of the cases there is information that a trumpet were further away than the normal during recording. So you get the feeling that it is in the far so to say.