"I should have checked it out myself." "Don’t blame yourself. It wasn’t your fault."
Because the hiragana ends with an う sound, you know this word is a verb. The kanji itself means blame so this is to blame.
Since this word consists of a kanji with hiragana attached, you can bet that it will use the kun'yomi reading. You didn't learn that reading with this kanji, so here's a mnemonic to help you: You say (せ) I did it. I say you did it. Everyone is going to blame everyone, apparently!