Polaroid cameras use instant film to produce a physical photo seconds after you press the shutter. The magic happens inside the film pack: after exposure, the film is ejected and develops before your eyes. For beginners, the most important decision is which film type your camera uses. The two main modern types are i-Type and 600. i-Type film is slightly cheaper because the camera has a built-in battery, so the film pack doesn't need one. 600 film is more expensive per shot but also works in vintage Polaroid cameras (like the 600 series). Unless you specifically want a vintage camera, stick to an i-Type camera for lower long-term costs.
There are also different camera series: the Polaroid Now (and Now+) are modern, automatic, and user-friendly. The Polaroid Go is smaller and uses a different film size (Go film) that's slightly cheaper. The Polaroid Lab is actually a printer for your phone photos, not a camera, so avoid it if you want a traditional instant camera. For beginners, the Polaroid Now (Gen 2) is the sweet spot: it's automatic, has a self-timer, double exposure, and uses i-Type film which is affordable and widely available.
Don't worry about manual controls or vintage authenticity—those are for later. As a beginner, you want a camera that 'just works.' Modern Polaroid cameras are designed with that in mind. The film itself has improved a lot, giving better color and contrast. The cost per photo is around $1-2 per shot, so you can experiment without breaking the bank. Expect around 8-16 shots per film pack depending on size.