Hiragana: ゐ ゑ ゔ
There are ゐ [WI], ゑ [WE], ゔ [VU] characters in some hiragana charts. Are they used anywhere? Should I learn them?
Even in modern Japanese, ゐ and ゑ are still used in some names (people, places, products,...). They are still among the legally permitted characters you can use when registering the name of a child in Japan.
For one of my favourite animes, the manga artist あらゐけいいち has ゐ in his family name. And when he romanises his own name he writes it as "Arawi Keiichi".
I'd suggest that it's not necessary to learn ゐ/ヰ, ゑ/ヱ, and ゔ/ヴ until after you've mastered the standard hiragana, katakana, and at least a thousand kanji. But eventually at some point it would be good to learn these less essential, obsolete kana for the very rare times you might encounter them. ^^
I've only seen them used in older (centuries older) history-channel type ❤❤❤❤. you'll only need modern katakana/hiragana and kanji. you could learn them if you're really interested but they'll probably only come in handy if you're friends with a bunch of old people with old Japanese books.ゐ andゑ are never used.ゔ is only used in kana asヴ.
I can predict the most likely scenario in which the additional no longer used kana would be useful to you. You're in a bar and you wanna order something and then you see this ヱビス thing and wonder what the heck is that first thing there, well that's katakana for ye, and you read the word as えびす (same as the Japanese god of luck). It's a beer. Basically, nope, don't worry about it, you can learn it for fun later if you want to, or even now, but they're literally never used.