The integrated mic definitely is not enough.
This may seem like a cop-out post, but you really should've done a little more research before purchasing a camera. Film making is an expensive hobby, and unnecessary expenses carry a heavy burden. Unfortunately, cameras are one of the more expensive pieces of equipment you'll need for shooting films. You don't want to be buying a new camera every year, because you realized that the last camera you bought lacked a feature you wanted. Is there any chance you can return the camera for a refund? If you can't, there still may be hope, but I'll get to that in a second.
Next time you're shopping for ANY equipment, be it a camera, a shotgun mic, or even tripod, DO A LOT OF RESEARCH! You don't want to rebuy equipment every year! In practice, saving up for the more expensive camera will actually save you a ton of money you would otherwise waste, gradually upgrading every few years. The same goes for ANY equipment you get.
I have a film maker friend that continues to make the same mistake, time and time again, and it's costing him A LOT of money. When he was starting out, he bought a dynamic mic for his sound needs. He thought it'd be enough, and told himself he didn't care about "broadcast quality sound". He paid a bit under 100 for the mic. After a month of using it, he realized that he really did not like the results it was producing, so he bought a cheap shotgun mic for 170 or so dollars. Eventually he wanted even more, so he bought a Sennheiser for 500. He gave his old shotgun away, and hasn't touched his dynamic mic since. That's 270 dollars of unnecessary expense he could've avoided if he had just saved up for a few more months.
Anyways, if you don't plan on getting another camera and you are a stickler for sound, you can get a field recorder to go along with a shotgun mic. You can then sync the audio with the video in post production. From what I've seen (I don't have one myself), field recorders are the professional route to go. Unfortunately, a good one might deal a heavy blow to your wallet. From what I hear, the FPS of your video will have an impact on how well it will sync with the audio, so if you want perfect sync, you'll need to get one of the pro recorders. A professional recorder will outlast any microphone or camera you may get. If you think film making is something you will be doing for a long, long time, then maybe look into getting one.
The cheaper solution is getting a regular digital audio recorder, and plugging your mic into it. I would not recommend going this route, because cheap audio recorders have terrible preamps. Terrible preamps mean bad sound, even if you have a great mic. If the only thing you care about is getting AUDIBLE dialogue, then maybe this will satsify you. But once again, if you think you might want something better down the road, just bypass this step and save yourself the unnecessary expense.
