By default, TurboTax saves files to this location (though it may be different on your PC): C:\Users\Your_Name\Documents\TurboTax\ with a folder for each year. You can go into the 2019 folder to find your tax return file. It will have the name of the person (or persons) you are doing the return for, and the extension .tt19.
You can also use the search tools built into Windows to find the file, if you saved them to a different location.
Once you find the file, you can copy it to your USB device to share with your other PC. Just remember to keep track of which version of the file you have where. If you make changes to the return on PC 1, you’ll need to copy that to the USB drive, and then to the other PC. If you are not careful, you may loose data, or even file the wrong version of your return.
If you’d like, you can rename the return files when they are not in use, or use File>Save As inside TurboTax to give the returns a different name each time you edit your return. Ex: tom.tt19 can become tom_v2.tt19 or tom_with_donations.tt19
