You may find lots of examples to do this. For this, check the main Quantum ESPRESSO repository and tailor them to your parameters. Additionally, utilize tools to simplify the initial steps:
Generate your structure using a resource like https://next-gen.materialsproject.org/materials/mp-984/. Keep only one layer and then introduce vacancies at the top and bottom to create a monolayer.
Use a tool such as https://www.materialscloud.org/work/tools/qeinputgenerator to create your SCF input file.
Perform the necessary NSCF and BAND calculations.
Finally, plot the band structure using the $bands parameters. Refer to the Quantum ESPRESSO instruction file for more details: https://www.quantum-espresso.org/documentation/