MAME games not showing up

Unfortunately you will need to have some means of writing to just an SD card. A lot of laptops have SD readers built in, so you would just need a SD micro to standard SD adaptor. They cost about as much as a packet of tomato sauce.

Have a look here. There’s some information on different card readers and more in this thread.

That’s your first point of attack. Then afterwards, you will need to locate yourself some “bios” files; especially for Mame. Consider it like a file that represents the physical hardware/arcade cabinet of the emulated Mame game. It’s a bit of a legal Grey area however, just like Roms themselves.

If getting an adaptor is too hard, try just getting some bios files sorted. DM me for any more info, since talking too much about this kind of stuff in the open is a great way to get a forum closed down.