Hi Felicia1212,
Welcome to the Apple Community, of Apple users, like yourself, doing what they can to help troubleshoot.
Wondering if the "Try again later" cancel site, is in the process of upgrading ?
Apple Support have articles online, that may, or may not help.
How to cancel a subscription from Apple / App Store:
https://support.apple.com/en-us/HT202039
Get help with subscriptions not billed through Apple:
https://support.apple.com/en-au/HT207865
Or
There is a "Get Support" link to Apple at top right on this discussion page,
or
See a list of Apple phone numbers around the world.
https://support.apple.com/en-us/HT201232
And ... if all else fails, and you still need to cancel, and still get "Try again later" on the cancel site
From the advert. for the free app: "Equalizer HD music player" on the App Store:
Seems the developer of the music player App is MWM.
There is a website for an App Developer of that name at https://mwm.io
There is a contact email address on their site.
(They may or may not know how to solve the cancellation problem).
All the best :-)