holding a note

what are some questions to ask a buyer who is interested in buying a vacant lot from us, with seller financing?

what are some recommendations about how to structure the note, or present it to the buyer.

we’re talking very little money here too. less than 15k. we own the property - paid cash for it.

also, i have a realtor who is listing it - 10% commission if he finds buyer, 7% if we find buyer. (current buyer we found). he said he needs copy of title to send us listing agreement.

i mean, for us to hold a note - i’d say 25% down and 10% interest for one year. is that reasonable?