Make sure you are aware of the difference between a hobby and a side business. Depending on the amount of your activity and your intentions, you may be required to report your activities as a self-employment business on schedule C.
https://www.irs.gov/newsroom/hobby-or-business-heres-what-to-know-about-that-side-hustle
And yes, everything you receive in return for providing a review is taxable income, using the US dollar fair market value of the item. If you believe that some items are worth less than their cover price due to their condition, you can use the lower value, but you should keep records of how you determined the value in case you are asked to prove it.
