In camtech, I talk about whether a camera has an on board XLR mic ports, or not, but I didn’t write much about it, mainly because I had little experience with battery management.
There are dynamic mics, which are usually rubbish, so a phantom mic is usually what you will go for, but the problem with phantom mics is powering them. If you’ve chosen a camera that doesn’t supply phantom power, then you’ll need a mixer like the Zoom H4n or more expensive, or a battery powered mic like a Sennheiser MKE series, or Rode videomic/pro, and they are the cheapest good options with shoe/shock mounts.
With batter powered mics, you have the main problems, 1, taking batteries through airports can be difficult, depending where you are, you won’t always be able to just have spares in your carry-on. 2, you have to remember to turn it on every time you use it, I’ve left it off by accident a few times, and it doesn’t just make the sound quiet, there is absolutely no sound. 3, you have to remember to turn it off after using it, because turning the camera off is separate, and if you’re in a busy situation, or not positioned behind it, you may easily forget, and waste your batteries. 4, you will always need to have a spare, because you won’t be 100% sure of how the battery is doing, and having enough batteries can truthfully be annoying. 5, if you are doing any kind of event, you won’t always be able to just switch out the battery, where things are generally not repeated. 6, having a tall microphone mount on your camera, like the Rode Videomic Pro can present problems with certain grip rigs, like my new DJI Ronin-m (practical review coming soon).
As for mixers, if you are doing a one man band (like most will, for the first few years of most work), then a mixer can be heavy, or just be difficult to find a place to hold/attach it. You also won’t have accurate level readouts on the camera’s screen. It will also need its own batteries, and I’ve seen professional sound people have to stop, and change batteries, so you are not magically exempt from battery woes. It will also take up more weight in carry on (you may not realise it, but if you are good, you will need to take jobs that require flying interstate), plus having an XLR cable, which is also prone to logistical problems.
These are qualities that you should take into consideration when choosing a camera without phantom powered XLR ports. Are you willing to do the extra work, and take that little bit of extra risk? If so, you are now well informed on the extra rigmarole that is involved, happy camera hunting!