Paints to choose from: Depending on the ease of use and amount of money, you may go for cheaper brands that have good reviews, otherwise, opt for comparatively better quality if you are aiming for long term and professional use. Watercolors, oil pastels and acrylic colors are a good choice to begin with. Oil paints require little more handling so begin with them once you have hands overpainting.
Canvas or sketchbook: There is a huge variety of student and professional level canvases. Even standard canvas can give a professional base with a coating of gesso (article coming up next...). To have it simple, a sketchbook is a handy option and is cost-effective. Best student-level canvases are available at stores like Michaels or hobby lobby or online.
Types of brushes: For beginners, there are super value brush packs available in stores for example- Artist's loft.
Color wheel: Helps in blending colors for beginners. It's easily available at stores like Michaels or online stores like amazon.
A well lit and ventilated space and a drink to sip on: A well-lit space helps while painting to avoid mistakes and ventilated room helps with exhausting any fumes whatsoever. Also, it's difficult to keep track of time while painting and chances are your hydration level goes down which affects the performance makes you less efficient. Any drink you wish to have serves the purpose.