The short answer is simply to: stay the course! There will be a lot of financial articles provoking fear and panic but you should ignore them all, and stay your financial course. Stock market crashes are expected, and the market always recovers and always goes up. Index funds (e.g. VTSAX) are still the best investment vehicle that requires very little work and great returns, but also a mindset of long-term thinking.
Historically, as you can see in the charts below, the market always goes up and the dips (bear market) is expected. That's why there isn't a special or unique way to financially prepare for a pandemic.
The only one thing you can do if inclined to do so, is if you have extra cash in an account and won't be needing this money soon (5+years), you can put more money into the market because any dips are considered a "sale." Never take money out at this time, but if you would like, you can put more money in.
However, if you regularly do dollar-cost-averaging (DCA), where you put in x amount of money per month in your accounts, then stay the course and continue doing as you normally would each month. And you will still have the strong returns you want during retirement.
Essentially, the best thing to do financially during this pandemic is stick to the same philosophy which is to "set it and forget it" and keep your focus on your long-term financial goals. This includes paying off high-interest debt, saving for an emergency fund, matching your 401K, contributing to your RothIRAs, HSAs, and 529s, keeping your finances organized, and investing in index funds. These accounts will all help you achieve your financial goals.
Now for the health aspect, the best advice is to wash your hands thoroughly and take the proper precautions recommended by the CDC. Stay safe everyone!