Tea
noun
The お just makes the word more polite. Since tea is so important in Japan, it gets the お. Otherwise, you should be able to figure out the meaning as it's the same as the kanji.
おちゃ
The reading is the on'yomi reading, just like you learned with the kanji.
わたしはお茶をのみませんでした。
I didn’t drink tea.
死ぬ前に、ベーコンのお茶づけが食べたい。
I want to eat bacon rice covered in tea before I die.
何故かおならがしたくなるので、もうお茶を飲むことはできない。
I can’t drink tea anymore because it makes me fart.