how can I get my music on my Computer play on my Sonos system

If you folowed this and it isn't working calling Sonos support may be your best option.

https://support.sonos.com/en-us/article/add-your-music-library-to-sonos

Have you been able to play music before? If so, a recent Windows update may have caused your issue.

Yes, I was able to play music before. I use iOS Apple.

Have you done any updates recently? 

Are you getting any errors? If so, what are the error codes?

 unable to add share folder to your music library (913) 

Have a look at these two links:

https://support.sonos.com/en-us/article/error-913-when-adding-a-music-library-share

My advice to you would be to get a NAS. You will not be susceptible to connection issues when Apple roll out security updates.