If you go to a gas station or liquor store you usually see an ATM. There are essentially Bitcoin ATM's you can google on google maps bitcoin ATM. Then you can go on an iphone app store and find a BTC wallet. If you don't want more of a trace go to your local bank ATM and withdraw cash. You then open the app and click on the machine. Your app will have a QR code or similar scan your phone to the machine, like a grocery store check out, then put your cash in and the BTC will be deposited to your phone's wallet.
Then you can send it to the marketplace direct, another wallet, or an exchange that has the Moreno coin which is completely untraceable compared to BTC like exchanging Dollars for Euros or Yen minus a little fee. Always purchase a little more than you need for fees. No Drivers license just a texted 6 digit code and that's all you need. Then send it to a market as others have explained and use PGP and make your purchase. Honestly if you are ordering from within your own country the government won't spend the time tracking down proving everything for a small amount of something. They have bigger targets, unless you purchased 50G of Fent then yes but personal use isn't worth the time/money. Try to buy in your own country. Anything from the Netherlands, Spain, South America, China, Australia and even Canada as it's being inspected by customs. Even if it they seize it they send you a letter and consider the address as burned and get a $10 a month P.O Box.
Let me know if you have any questions.