Hi and welcome to the forum.
Assuming you have compiled your Scanner program successfully, you ought to see that program in BlueJ's main window displayed with a non-shaded box.
Right-click that box and select void main(String[] arguments) to run. A method call box will pop up and by default has {} passed. Generally you can just click OK here to run, although this is subject to how you have coded your program.
Or are you attempting to run your Scanner program from a command prompt window? If that is the case the simplest thing is to first change directory to the location of your compiled Scanner program, then when in this directory enter the command java name of scanner program without the extension. For example if your program is named ScannerDemo.java then to run from command window type java ScannerDemo then press Enter key
Are you getting any specific errors when you attempt to run your Scanner program?
Can you upload the program to the forum. I could take a look to see if there is any code issues.
Are your environment variables set up in Windows 10 (i.e. PATH and CLASSPATH)?
When you installed the latest BlueJ for windows, did you choose the bundled version that comes with JDK 8, or just the actual Blue J program itself? You do need Java Development Kit (JDK) at a minimum installed also to be able to use BlueJ.
Regards,
Regedit32