Your primary task in this kind of essay is to write a clear thesis statement. As a persuasive essay, you are already making an argument. Your thesis statement is going to state that argument and guide your writing. Additionally, the writing prompt states that you have to address the "counterarguments," and that can be incorporated into the thesis statement no problem. Create a thesis statement that is formatted using a complex sentence. This will force one half of the statement to be a dependent clause. This half of the thesis will bring up arguments that are counter to the main argument which is contained in the independent clause of the thesis statement. Feel free to fine tune the following thesis statement.
"Although the recent shelter in place and social distancing orders seem to be hyperbolic and reactionary, in reality these orders are the two most effective ways to slow the spread of the virus."
This thesis statement gives you plenty of latitude to explore how and why people might be ignoring the social distancing and shelter in place orders. Your essay could explore how people might dismiss the orders as media-driven hysteria. The essay could also explore human psychology regarding not fearing something that can't be seen or felt until it is too late.
As for supporting the shelter-in-place and distancing recommendations, the essay should spend time discussing how this particular virus is transmitted. You can certainly go into dormancy periods and how long the virus stays active on various surfaces. Feel free to discuss how long a person is contagious before showing symptoms of the virus. Additionally, you should discuss how social distancing can "flatten the curve."
Regarding the start of your essay, you need a solid attention getting hook. One effective hook is to ask a question. If the first sentence of your essay is an interrogative sentence, a reader is immediately under pressure to think of an answer, and he or she is also curious about what your answer is. A curious reader is a motivated reader. Another effective tactic is to start the essay with a bold statement designed to get an emotional response out of a reader. By emotionally engaging a reader, you are targeting a reader's pathos. This is a powerful area to target for persuasive essays. Feel free to open the essay with something designed to get a strong reaction, such as, "People that are not sheltering in place and practicing social distancing are guilty of murder or manslaughter."
As for sources, stick with online sources that are .gov or .org sources. The Centers for Disease Control, World Health Organization, and the Mayo Clinic are all going to be great sources.