SFDCWallah

If you are also facing this.

Check the below things:

1. If the email id that you are using, you are opening in outlook. It could be possible it’s restricting due to it’s new features or
2. Your antivirus is making url immediately expired.

Solution:

When you are creating your trial org, use the email id which you are not going to open in outlook.

For example: You can use use any personal Gmail email id to create trial org and once you get the verify account mail from Salesforce you should be able to generate password for your org.