It sounds like you're leaving the US because you are abandoning your permanent residence. In that case, you are not eligible to return on the basis of your green card. See 8 CFR 211.1(a), which provides that the green card may be used by someone who is arriving "as a lawful permanent resident returning to an unrelinquished lawful permanent residence in the United States."
Instead, you should relinquish your permanent residence (using form I-407) and apply for a B-2 visa (although this may not be possible these days because of COVID-19).
You should also be aware that retaining your green card means that you are liable to report your worldwide income to the IRS, and potentially pay income tax on it, even if you are not physically present in the US.
If, on the other hand, you intend to return to the United States eventually and resume your residence there, you can indeed use your green card to enter the US, provided you have not been absent for more than a year. Talk to an immigration lawyer before doing this, because there is a good chance that the US government would find that you had abandoned your permanent residence even if that wasn't your intention. A lawyer can help avoid this.