If most of your earnings are from domain parking, affiliate programs, etc then it's likely regular income ...
Unless your income exceeds a few thousand (I'm assuming you had no job the entire year), it may turn out you owe little to no tax; regardless you would likely still need to file annual federal, state, and local tax returns come April.
If your total annual earnings are under several thousand, then using a tax preparer come tax time may be adequate.
Otherwise, if your total annual earnings exceed several thousand (or you truly feel it will), then you should seek some assistance from an accountant or at minimum someone (perhaps your parents / their friends) who has already established a business in your area...
At minimum, you will likely need to get a business license (cost typically nominal) and potentially make quarterly estimated tax payments - it's not the end of the world if you don't, when first starting out, but you may end up having to pay a bit extra in interest and potentially some smallish penalties come tax time.
Ron