The meaning of this Kanji is “one”, as in the number. This is easy to remember because it’s one stroke laying on its side.
いち – Ever been laying down, like this Kanji, trying to sleep but can’t because you’re so itchy? Use that to remember いち.
一 ( いち ) = One
This one is easy, because the vocab word shares its meaning with the Kanji.
一つ ( ひと・つ ) = One thing.
This one uses the kun’yomi reading, which you can tell by the fact it’s accompanied by some hiragana). Literally, it means “one thing”. For instance, one car, one phone, one ____.