How many payments can I accept on the free plan?

What does it mean that I "receive 1 payment" in the Starter Level? I've linked my JotForm to PayPal. I'm hoping it doesn't mean only 1 person can pay on my form.

Yes, that's basically how the payments limit work, you can receive one single payment only through any of your forms with a payment integration. 

If someone submits your form for the first time, then that will count as one payment. 

If you have more questions, please let us know.