What is your definition of "competitive"? Do you mean against other 14 year olds? I'm not aware of any meets that are going to break up competition by the year, at 14 he's probably a 9th grader and will be competing against other high school runners - so kids from 14 to 18 years old (or maybe an 8th grader I guess).
If he's in high school and you are asking about competitive times, you can Google those for your state from previous years. To give you a reference point, I live in WV. On any given year, a 100m runner would need to be consistently faster than 12 seconds to be among the top 25 in the state - and we're certainly no mecca of track and field talent. To truly compete, meaning have a chance at a winning, he'd need to be pushing 11 seconds.
If he's an 8th grader, meaning his competition are all middle schoolers, here in WV a 12 second 100m race would give him a shot to win at most meets, though we do see the occasional 11.5s from an 8th grader. Again, the results for past years in your area should be readily available online.
EDIT: From the comment you posted above, a time without spikes for anything shorter than 400m is kind of irrelevant, and even at 400m traction plays a big role. If they did a good job hand timing, then he is likely capable of well under 12.6s. The harder you're trying to push forward, the more traction matters - walk across a tile floor in your socks, then try to go from standing to sprinting in them. If this was his first real 100m on a track, he will also be noticeably faster with more practice - he's probably never ran out of block before and never been taught how to properly start in a sprint race, which will both cut serious time off of the final product.