Edible flowers are used in salads, entrees, desserts and beverages. So which ones are safe to use? Not all flowers are edible.
Do some research. Good reference resources will guide you safely. Always be sure they are not poisonous. Do not use flowers from florists, garden centers, or picked from the roadside. Introduce them into your diet in small amounts as some can have unpleasant side effects. Not all parts of the flower are edible, so research can help determine which parts to use.
Here are some resources:
www.johnson.k-state.edu/docs/lawn-and-garden/in-house-publications/perennials/Edible%20Flowers.pdf
https://extension.umn.edu/flowers/edible-flowers
https://extension.colostate.edu/docs/pubs/garden/07237.pdf
https://extension.psu.edu/a-consumers-guide-to-edible-flowers
https://content.ces.ncsu.edu/choosing-and-using-edible-flowers-ag-790