I read that you must past zakat on wheat, dates, and raisins? Does this mean if I buy them?

Do I need to keep track of the price of every loaf of bread and box of raisins I buy at the store, and pay 2.5% of how much they cost me in all at the end of the year?

No. Zakat applies to large amounts of them—so basically farmers who grow them.

So this does not apply to you.