Well, i highly doubt anyone here or other places will give you one for free without buying reseller hosting or so.
what u can do is sign up with clientexec or whmcs then you get a free enom domain reseller.
whmcs as other people and myself in various posts is the clear leader for control pannels and their extention to this is perfect for those hosts who wish to offer domains as the free resellers, both of which cost considerable setup costs otherwise and given for free.
To be a domain reseller of Enom.com you need to pay setup fee its for sure, the rate per domain depends on your initial deposit you pay to enom.com, it varies from $10.5 to $8 per domain according to deposit.
There wont be much profit if you only sell domains, people always look for stable companies not newbie's for domain registration, issue this with hosting package