Welcome to the forum.
Yes cameras using regular SD cards are extremely rare now, if not all gone.
What card to get depend some on the camera, brands like Thinkware and Blackvue seem to be a bit fussy what cards they like, many other brands not so much.
In general today i recommend getting a endurance card as they are covered for warranty when used in dashcams, something regular memory cards are most often not, and price for endurance cards are quite fair these days.
Many dashcams are also provided with a USB card reader, not the fastest one of course but otherwise it plug into a USB port in your computer, and come even have a #2 plug and OTG support so you can use it as a card reader on your phone too ( most often android as ISO are a bit crazy )
you of course need the correct plug for your phone.
Or you can get a regular USB card reader for your PC.
Some dashcams also act as mass storage devise if you plug it into a computer, but this way they can be slow, though not a major issue if you are just grabbing a single file now and then.
Playing video directly off the camera in mass storage mode, or using a slow card reader or a fast card reader but on a old slow USB port can cause lagging and freezing, in that case copy file / files to computer before playback.
If you use MAC computer or phone, it can some times cause problems for some dashcams so it is recommended to format the memory card in the camera after it have been in contact with one of those Apple devises.
Many cameras today also have wifi and APP support, so you can also transfer footage to a phone / tablet that way, mind you it is also slower speeds but just fine just grabbing a file or two now and then, but for bulk transfers a card reader on a fast USB port are the best and will give the full read / write speed of the memory card.
you can not access camera wifi from a computer, it do require a android or IOS APP.
For a single camera model you can make do with 64GB and 128GB for a dual channel system, larger cards are not always supported but otherwise going 256GB will not hurt, and even such a big memory card are surprising cheap nowadays ( look for memory card with A1 branding if regular type )
Write speed of the card should in general be 40 MB/s or faster, and most SDXC cards have that today.
And when buying memory card, make sure to do it local where you can get goo service and warranty, i use local stored and nearby ( EU ) Amazons as Denmark are too small for its own Amazon.
it also make sense buying dashcam itself to spend a few dollars more local VS buying from far away if you need support.
