1. Where can I find manga with Furigana →Those are websites of the magazines for boys. They have sample pages. 週刊少年サンデーhttp://websunday.net/ 週刊少年ジャンプhttp://www.shonenjump.com/j/ 週刊少年マガジンhttp://kc.kodansha.co.jp/magazine/index.php/02065 2. how you actually translate this question into Japanese: 振り仮名のマンガはどこに見つけますか。 or maybe: 振り仮名のマンガはどこに見つけられるか。 →振り仮名の振ってあるマンガは、どこで見つけられますか？

Some manga with furigana that I have are 君に届け、神様はじめました、チーズスイートホームand 菜の花の彼。But these (besides Chi's Sweet Home) are mainly 恋愛マンガ so I'm not sure if it's your cup of tea. :)

Okay, now give the Beginner Level :D

1 How about this one? Japanese Lessons with Manga https://www.wasabi-jpn.com/japanese-lessons/materials-for-japanese-lessons-intensive-reading/ You can learn Japanese via Manga with Furigana, English translation and explanation.