I am trying to learn about 125 new songs on multiple instruments. Were do other musicians get sheet music from? I am looking for an online source. I dont want to pay per page, but am willing to pay a monthly subscription.

Well, what I can suggest is Virtual Sheet Music, which is the company Musicians Page is part of:

https://www.virtualsheetmusic.com/

We have a Membership which gives you very special benefits:

https://www.virtualsheetmusic.com/unlimited.html

Clarinet Institute of Los Angeles has all sorts of free music online. Solos, clarinet & piano, books, chamber music, etc. No copywrite, so you can just print it. Maybe other instruments have such sites as well?

I have recently looked into Sheet Music Plus for publishing a piece I have written. They seem to be a good way to go and have tons of music online, along with very good reviews.