There's actually a 'caution' in the manual about turning off the Venus wifi, but there should be an easy way back.
To much to rewrite the manual here. All your questions should be answered here (and the ones you haven't asked - yet): https://www.victronenergy.com/live/venus-gx:start
Also the CCGX manual covers a lot more stuff common to both: https://www.victronenergy.com/live/ccgx:start
What you use for internet connection is pretty much stock stuff we all use commonly. If you have VRM access to view, then all should work for you.
The SD card is also in the manual: "SD and SDHC type microSD cards of 32 GB capacity and smaller are sold containing FAT12, FAT16 or FAT32. They can be used without a problem, unless they are subsequently re-formatted to a different file system".
Sorry to make you work for this, but you did say you 'weren't shown'. Now you have been.. :)
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