Most phones carry two or three subscriptions nobody uses any more. Here is where each one hides, and the last one never shows up in the Play Store at all.
Play Store > profile icon > Payments & subscriptions > Subscriptions lists everything Google bills you for. Most people find at least one they stopped using.
A free trial is a subscription that has not charged you yet. It renews on its own the day the trial ends, so put the reminder in for the day before.
Google Play keeps your access running until the end of the period you already paid for. There is no reason to wait until the last day to cancel.
Some apps offer a pause. Open the subscription, tap Manage, then Pause payments. Durations run from one week to three months, starting at the end of your cycle.
Cancelling stops the next charge, never the one that already landed. Google Play's self-service refund window is 48 hours; after that, you ask the developer.
That list only covers what Google charged you for. Anything you signed up for on a company's own website has to be cancelled there, inside that account.
Subscriptions you started on an iPhone keep billing through Apple long after you move to Android. Open Settings, tap your name, then Subscriptions to clear them.
A Google One plan can be shared with up to five other people in your family group at no extra cost. The exception is the 30GB Lite plan, which cannot be shared.
Add-ons billed by your carrier never appear in the Play Store at all. Open your carrier's line details and read every recurring item on the bill itself.
No app and no card needed. Clear the Play list, check the old Apple account, then read the carrier bill for the charges Google never saw.