It is possible to earn some curation at 15 SP but not terribly likely. There is a minimum 'earning' requirement of 0.001 SP on a curation reward where anything less than this is instead a zero (since this is the smallest split possible for steem.) Essentially you'd have to getting your vote in before any big voters, then having the post earn a large amount of $. Also, this all is assuming your vote power % is at or at least near 100%.
Typically (because of this) I recommend for people starting off (with the 15 SP) to focus more just voting for things they like simply because they like or want to support them versus for curation.
Ok makes sense or steem in this case. Thank you for answering in detail :)