This list applies if you are painting in oil. Demos will be done in oil but you may work in any medium.
Portable easel
Small sketchbook and graphite or charcoal pencils
Palette
Paint cups
Brushes (flats preferred, various sizes)
Turpenoid
Pigments: (colors in bold type strongly recommended)
titanium white, cadmium yellow light, yellow ochre, cadmium red light, ultramarine blue permanent green light, viridian, cobalt or cerulean blue
Primed canvases or panel boards (variety of sizes and formats recommended)
Painting knife
Paper towels or rags
Trash bag
Warm weather gear: hat, drinking water, sun screen, insect repellent