If you use AS to build muscle at this point you'll lose most of it when you stop. The only way you can keep your gains is to have mature muscle to build on. Give it at least another year or two. At that point your cycle would be a good beginner cycle if you doubled the doses.
doubling the test, yes. Doubling the nandrolone-- 500mg is over the side effect shift point IMO (though it obviously varies quite a bit- and changes over time)
Damn they are starting younger and younger every day! Seriously bro, if you have only been lifting a year, you are nowhere near your genetic potential. Stay off for another year or 2 and your could make some solid natty gains.