You can do some really fun things with a rambo blender, but I would never tell you that you absolutely had to buy one.
Healthy eating doesn’t require any special equipment, but here are the tools I use on a regular basis and would be used to make the recipes: a good knife, a cutting board, pots and pans, various utensils (spoons, ladles, flippers, etc), and some kind of blender or food processor.
I sometimes use other tools (like a citrus zester and a garlic press) but you can get by if you don’t have them.