Due to the fact that you have never been in any kind of sexual encounter, the chances for this bump to be STD are zero.
Considering your age, and no history of sexual activities, this bump is most likely only a pimple.
Acctually, pimples can occur anywhere where sebaceous glands are located.
They result from the blockage and inflammation of a sebaceous gland, and, can even occur on the penile shaft.
The number of pimples that occur on the penis can range from just one to many and can sometimes occur in rows.