I remember when I first tried Facebook ads. I had an online shop that sells mountain bike parts. I invested about 500$ in the campaign and the results were similar to yours: 0 conversions.
Four years later, I know what I did wrong: I didn`t have experience and I didn`t do a great targeting job (region, time of day to display the ads, even the selected ages were wrong, I also did not test multiple scenarios).
One more thing: When you invest money in these kind of campaigns you aren`t loosing money, even if you don`t get any leads, you ARE BUYING DATA that will help you later.