N5
や
Things like, And the like
コンビニでお水やおかしを買った。
I bought things like water and snacks at the convenience store.
Explanation
「や」 joins two or more nouns, picking two or three representative examples from things of the same kind and hinting that there are others: 「机の上に本やノートがあります」 (There are books, notebooks and the like on the desk). It often goes with 「など」: 「AやBなど」.
Mixed up with
「と」 lists everything: 「机の上に本とペンがあります」 means the desk has only a book and a pen.
「や」 gives examples: 「机の上に本やペンがあります」 means that besides a book and a pen there may be an eraser, a ruler and so on.
Adding 「など」 stresses 'and so on': 「野菜や肉などを買いました」.