Whatever you do, dont use coinbase, you are going to get a lot of issues in there and it is the worst exchange that has ever existed. Better to use localbitcoins and buy your own bitcoins to the person that you most trust.
Because it is a p2p exchange, you can choose to deal directly to the seller in person and it would be a much more safer operation, i really suggest this exchange to you.
I sell my bitcoins to a guy who is always buying bitcoins, and all the transactions are smoothly.
It is the best exchange that bitcoin has at the moment.
I remember my first experience with coinbase. My Oh My! It was an awful one and before they could even rectify my issue, my heart beat was hugely on the high side looking at the amount of money involved. However, I have tried Kraken several times and it has been Okay.
Localbitcoins seems to be the most places I get most of my stuff for now but you should still be careful anyway. You can also try CEX, I have seen some good reviews about them and I am hoping to try them out soon.