Hank here from Shopify.
These things can happen when it comes to something you do not use, so don't worry about slowly forgetting about your trial! However, once it comes to finances, I want to ensure that you are not paying for a store you are not using, and not worrying about college fees.
Normally, once the trial period is finished, and no plan has been selected, the store would naturally cease to exist until a paid plan is chosen.
If a plan was chosen, then it enters the billing phase once your trial expires. You would have a set billing date (every 30 days, which you would be notified), where your monthly payment would be made. Now say there is an issue and the payment could not be made, the system would automatically attempt two further times to make a payment to the account to pay the 30-day subscription.
If however, after the third payment that no fees are collected, then the store would go into a pause or frozen status. This essentially means that to reopen, close, or continue with the store, the outstanding payment would have to be paid, then it would revert to the standard 30-day billing cycle.
So there are a few options that can be done if you are wishing to close or continue with your store. If wanting to close, you can let the automatic attempts continue, and after the third, the store will essentially start to close. Should you wish to reopen this, you would just need to pay the outstanding fees. Then if you want to pay the fee, then close your store, which can be done also by following the steps located in this guide. In some situations, we then may be able to provide a refund for your Shopify subscription if within the past 30 days. However, third-party app charges are decided by their developers.
Let me know if you have any questions, or if you need further assistance with this, my friend!