Since this word is made up of a single kanji, it should use the kun'yomi reading, but you haven't learned it yet. Here's a mnemonic to help you:
What game has the most things in it? Monopoly (もの). You can choose from a bunch of random things to play as, you know? And no one actually knows what those things are. What's a thimble anyway? Just call it a thing.
What is that thing Masaru has?
Don't treat my dog like a thing!
My three favorite things are chicken, fried foods, and rice.