if you start that young you should make sure you are ready to commit to this lifestyle.
it is expensive, it is addictive, and it takes a lot of time out of your life. taking all the health factors away for a second just think of the money you are gonna spend on this rather than invest in your education, business, or career and decide if the money factor is gonna click for you. then look at the health risks in terms of the younger you start the sooner you will be on HRT. it is likely you will continue cycling for years and years to come as the muscle gains will become hard to get away from and you will want to continue building muscle.
it makes more sense to live your life and figure out everything. then once you get your shit together and have the money and time to spend on this amazing lifestyle you are ready.
if you see yourself as a weekend warrior (as 99.9% of guys your age do) then you should NOT mess with steroids yet simply because you can be a weekend warrior without them. when i was your age i had a gym membership but i would go 2X per week .. MAYBE 3X. i owned my own house, I had a business going.. those were my priorities, NOT lifting. once i got older and had the time and money is when i decided to open the can of worms.. been absolutely addicted since... i workout EVERYDAY. yes EVERYDAY.. if its not the gym it will be like what i did this weekend .. i hiked 3X about 15 miles total