How do biologists infect cells with viruses within a lab setting?
You'll probably want to consider whether HeLa cells are the optimal cell line for acheiving your objectives. This paper shows minimal change in cell viability of HeLa cells innoculated with SARS-CoV and SARS-CoV2, but it's probably a good resource for how cell-culture infections are performed. This paper claims that VeroE6 is the standard cell line for producing viral stocks of SARS CoV-2.

Best of luck with your proposal.