There are many ways to purchase bitcoin. We recommend using the mycelium bitcoin wallet for android.
First download the wallet here: https://play.google.com/store/apps/details?id=com.mycelium.wallet
Next setup your wallet:
Tutorial for local trader on Youtube:
With local trader option you create an account and meet people in person to buy and sell bitcoin via cash.
Setup you local bitcoin account to buy bitcoins via local trader with this tutorial.
BUYING WITH CREDIT CARD
We do not recommend buying with a credit card but if you do, then you can purchase within the mycelium app with Glidera.
WHAT ABOUT THE FLUCTUATION IN PRICE?
Mycelium also has Coinapult built in where you can lock in a price in USD. It does take a little longer and price is a little higher but prevents you from losing money in the case of a crash.
ALWAYS PURCHASE 10% MORE THEN YOU WILL NEED.
There are charges for transfers and different rates. Remember bitcoin is sold in bits and traded on many exchanges. This means if you purchase $300 on one exchange then the person you are paying may show $285 or something similar. The safe thing to do is make sure your exchange is based off Bitstamp, Coinbase or a reputable exchange.