Bought a new card for the 2610. Apparently, I need to format it but can't find any such option on any of the drop,down menus of the map source software. Any suggestions?
When you format the SD card you must use FAT or FAT32 file formatting - Garmin devices don't recognise exFAT (allows file sizes over 4GB) formatted cards. More info here.
If your pc doesn't have an sd card slot, you can get USB/sd adapters.
Forget all that.
Get an adult to do it.