If all goes well, SN1 could attempt a test flight as high as 20km later this spring, although SpaceX has not yet obtained a launch permit from the Federal Aviation Administration.
The SN1 vehicle will not attempt the orbital flight, however, as that will come from future iterations. Musk said his best guess for the orbital flight test vehicle will be SN3, SN4, or even SN5. "This is very rapid iteration," he said.
https://arstechnica.com/science/2020/02/elon-musk-says-spacex-driving-toward-orbital-starship-flight-in-2020/