After the trial period on quickbooks (30 day). I can't see anymore the journal entry, accounts, etc I made... Is is automatically erased?

Hello there, @Matthew11_2-. It'll be my pleasure to share some details about what happens to your data if your QuickBooks Online (QBO) subscription has reached its expiration date.

In QuickBooks, once your chosen free trial subscription or a subscription you've bought has reached the expiration date. You can still access the data inside that account. However, you can no longer make modifications to your files. Also, please be aware that you can only have the Read-Only-Access for a year. Once it reaches a year, and you still haven't renewed your subscription. You'll no longer have access to your files.

Since it's only been 30 days, I recommend utilizing the Audit log feature to determine if there are changes made to your account causing your data to disappear. I'll gladly input the steps below to proceed. Here's how:

1. Access your QuickBooks Online company.
2. On the top right corner, click the Gear icon and select Audit log.
3. Use the fields on the page to choose the appropriate User, Date, or Events filter to narrow the results.

See this page for more information: Use the audit log in QuickBooks Online.

If the issue persists, I'd suggest performing basic troubleshooting, like clearing the cache and cookies in your browser. Although they help increase the loading capacity of your browser, too much of it can cause the operation to slow down.

Visit this page for further guidelines: Clear cache and cookies to fix issues when using QuickBooks Online.

In addition, I've got you this article in case you'd like to reactivate your account: How to resubscribe to or reactivate QuickBooks Online. 

I'd also leave this helpful article about managing subscriptions in QuickBooks: Manage your QuickBooks Online subscription and update billing.

The Community is open 24/7 in case you have any additional QuickBooks-related concerns, @Matthew11_2-. I've got your back, and I'll help you again. Take care, and have a nice day!