Keep in mind what said above aswell.
Please also read this before going bankrupt/ waste cash.
https://www.google.co.uk/amp/s/blog.bufferapp.com/facebook-ads/amp
Good luck .
Ps. Adwords and bing are better as they dont have bots running around helping to crush your cash , facebook does....
Ppl still seem to make good money from facebook .
I think better trying it free with spam group posting......(( buy facebook accounts and spam the niche you want traffic from , each time a account dies re load another account go agin....
I am pretty sure most adds are from group posts anyway ...