Paysafecard is available at multiple different retail locations in a wide variety of countries. We cannot list every single retail location here, for obvious reasons, but if you live in a major city you will absolutely have this service at your disposal. Moreover, on the Paysafecard website, you will be able to find a map which lists all of the locations where the vouchers are available, as well as, set it so that it shows where the closest one is.
Just for clarification, you do need to be over the age of 18 in order to purchase a Paysafecard voucher, which also incidentally happens to be the legal gambling age in many jurisdictions.