Hi
To view and manage your current app subscriptions - and to turn off Automatic Renewal for any of them - follow the instructions here:
View, change, or cancel your subscriptions - Apple Support
Once Automatic Renewal has been turned off, a subscription will end at the end of the current subscription period.
If you have forgotten your Apple ID and/or password, follow the instructions here:
Be sure to follow the steps here in respect of your lost iPhone:
If your iPhone, iPad, or iPod touch is lost or stolen - Apple Support