Try reading and learning your question is too broad
Choose products that people actually need and can't live without, not gimmicky gadgets and shit that no one really needs nor can afford.
Just my couple of cents, which I might've as well saved for a new Towel, Coat, or Mug, all of which are really needed in my household.
I recommend choosing products that YOU like so that you can write some nice original content related to these products. Do you like Sports? Music? Movies? Fitness? Health? Make-up? It's better to choose something you are passionate about because then you will be more dedicated to the success and have more fun working on it.