Keep in mind that this first exposure to cells is only to have students gain the concept that all organisms (plant, animal, microbial) are comprised of cells, an estimated 40-60 trillion in the case of a human, just a single cell in case of protozoa and bacteria. Allow them to chose various animal tissues (fat, skin, liver, intestine, etc.) and plant tissues (leaf, stem, root tip, etc.). Pull up photomicrographs to that tissue and guide them in discerning the cellular structure. Type into your browser: photomicrographs of ____ tissue/ putting desired tissue in the blank.
Couple this, if possible, with enabling kids to use a microscope to make their own observations of fresh tissues, e.g., onion skin and/or Elodea leaf, as described in the text. Pointers on making a slide and using a microscope are given in the following video: