I am one person on the counter with no manager. Is a POS system for a small restaurant like mine too much?

It works fine with one person, because you add yourself with the role Everything and you are the cashier and the manager at once. Ring up sales, press Lock when you step away, and use Put aside when somebody goes to the car for cash. You do not need a printer, because the receipt shows on the screen and can be sent on WhatsApp. Open the day with a float and close it with a Z report, and Reports → Shifts and the POS keeps the history. Setup takes about ten minutes once the add-on is on. The POS and the counter tab in the docs is written for exactly this size of place.