Technically speaking, your business was still "open" in 2019. So go ahead and file the SCH C showing zero income, and also showing any expenses that may have been incurred. This will keep things "on track" for you with the IRS. Especially if any of the following are true;
1) Your business has depreciable assets.
2) You claim a home office
3) You claim any business vehicle use, even if that use is less than 100% business use.
