I think i mentioned that somewhere, but yes on first use the camera might ask to format the memory card, it should not do that again down the line unless there is a problem.
Once you have said yes to formatting the memory card, then as i recall the camera go strait to normal and start to record on its own. ( recording verifiable by red dot on LCD screen and red LED flashing )
But it is still a good thing to do a in camera format once in a while, every couple of months or so. off course if you drive 8 - 10 hours every day ( a lot to me ) then you might do it more often.
What the format do is restore / set the FAT ( File Allocation Table ) on the memory card, so its known to the camera what are available and where on the memory card, over long time use things can get a bit fragmented by all this writing and deleting on the memory card.
This are the same for thumb drives or hard driver, they all have some form of FAT, those can be called FAT - FAT32 - NTFC and other i am sure, but the ones i mention here are the most normal ones for computer ( PC ) use.
Not something to worry about, its just things that's there to make them work with other things like a computer or a camera and so on.
Off course if you have been driving for some months with the "full" memory card you might want to save some incidents first by copying those to the computer ( use copy and not move to computer )
But personally i get things i want to save off the memory card as soon as possible.
I said "full" cuz the memory card dont really get full, when it get to there the camera will start to delete the oldest recordings on the memory card to make room for your new recordings.
This is what we call loop recording, continuously looping the storage on the memory card, by deleting the oldest stuff to make room for new stuff.
Only things in the RO named folder on the memory card are safe from this routine of loop recording, in the RO folder go events, either manual made by you pressing the round button on the camera, or if you have G sensor turned on, or use motion detect.
G sensor trigger on bumps, that that's all bumps or sudden brake or acceleration, so it is close to impossible to filter out things you dont want, and if you dont filter it good the RO folder on the memory card will just grow to where you might not have room for anything on the memory card.
Besides the camera are recording all the time, and i am sure you will feel if you get bumped by another car, and if you use a larger sized memory card it will still be several hours of recording before the recording with the bump will be deleted if it is not in the RO folder on the memory card.
Motion detect used when parking are also nasty, every movement in the fame of the camera will trigger a recording, and its also events and so Read Only ( RO ) so they too can fill up memory card leaving no room for regular recording.
When i get around to use parking guard one day i will only use G sensor, that way a semi or a bus or some one hitting my car will be all triggering a event while i am parked.
I think the rule of thumb are, that on a 32 Gb memory card you can have 4 hours of recording - 64 Gb 8 hours and 128 Gb 16 hours of video ( rough numbers )
So if you have a 32 Gb memory card in your GC, then you can drive 4 hours before the first 3 minute file of you setting off from home will be deleted to make room for your current driving.
But if you dident have a accident or anything happen on your drive up until now then all that footage from the previous 4 hours of driving are just garbage.
You only want to save major things like a accident or something else you might want to share or save.
All the other footage of you just going uneventful from A to B, that's just garbage so to say.
Once you get going, then some day down the line when you look at your memory card you will form a standard for how many days of driving you will have on your memory card based on your patterns of driving.
If you are anything like me you will soon see that it are often the the same drives you make.
Me i drive to visit my friend ( 40 minutes each way ) or go to visit my old mother that's a 30 minutes drive each way, and then i drive to the store to shop, and i once in a while drive to the burger joint or pizza joint yo get some food.