「々」 is kanji 「同」's glyph 「仝」 in origin. As Rebecca-san already explained it's uesd when you want to use the same kanji twice. And only the kanji iteration mark 「々」is commonly used today. 「ゝ」 is used when you want to use the same hiragara(平仮名) twice, and 「ヽ」 is used when you want to use katakana(片仮名) twice. For example, 「ここ」(here) can be wrote likes「こゝ」, 「バナナ」(banana) can be wrote likes 「バナヽ」.

々 is used when you want to repeat the sound of the kanji that came before, it depends on the kanji but sometimes the 々 can take on the tenten sound of the kanji that came before. for instance, in 時々 the 時 is pronounced "toki" and the 々 is pronounced "doki", but depending on the kanji it can just repeat, such as 色々, the 色 is pronounced iro and the 々 is also pronounced iro Can you use an example of the other two? I don't think I've ever seen them before, but I'm not a native Japanese speaker

Thank you! ありがとう！(^_^)