It's good to wet your hair before shampooing.
This USB is important, so please be careful not to get it wet with coffee or water.
Since I was dumped by my senpai, I've been soaking my pillow with tears.
This word consists of kanji with hiragana attached. Because the hiragana ends with an う sound, you know this word is a verb. The kanji itself means wet or damp, so the verb version is to wet or to dampen something.
Since this word consists of a kanji with hiragana attached, you can bet that it will use the kun'yomi reading. You learned this reading with the kanji, so you should be able to read it already!