Whats your goal? do you care about everything being in your name, or traceable to your computer? If its all on the up and up, investing etc you can just use coin base.
If you are going "gangster" there are sites that put you together with people willing to buy / sell BTC for cash. You meet up in person, pay, handle the transfer. Learn to use BTC mixers etc.
edit: forgot the link:
LocalBitcoins.com: Fastest and easiest way to buy and sell bitcoins (cash)