There are several books excellent at teaching grammar. My own favourite is The Elements of Style by Strunk and White (various editions exist, all do the job).
While precise grammar is appropriate for some audiences, I would discourage valuing it too highly. If the central characteristic of writing well is to put an idea in somebody else’s head, then shouldn’t we optimize for efficiency?
As someone about to embark on a compulsory cross-country flight for work, I empathize with your decision process. Thanks for taking the time to write it out.
In your shoes, I would do as you’ve done. People who choose to travel implicitly accept risk, including the risk of exposure to people who choose not to protect themselves and those around them.