hi jason, i had my first sgc when i was fifteen and had no probz apart from wait(because of reference from my school, apparently this is not essential, if only id known!) you dont need land to acquire a sgc but rather a good reason such as clay shooting , rough shooting etc.
sorry dnt no if it differs in scotland but here in wales was no probz and also they cant refuse you if you tick all the boxes eg pass checks, security adequate, good reason and countersignatory is ok so dnt worry 2 much.
only thing you cant do is buy guns nd ammo.yet!!
hope this helps