The banjo is a stringed instrument with a circular body like a drum. The most common type, and the one best for most beginners, is the 5-string banjo. It is played in two main styles: bluegrass (with fingerpicks and a bright, driving sound) and clawhammer (with a downward brushing motion and a more melodic folk sound). Both styles use the same banjo, so you don't need a different instrument to try either approach.
There are two body types: open-back and resonator. An open-back banjo has no back panel, so the sound escapes backwards. It is usually quieter, lighter, and often favored by clawhammer players. A resonator banjo has a wooden back that projects the sound forward, making it louder and punchier. That's the classic bluegrass banjo. For beginners, either one is fine. If you love bluegrass or want to play with others, a resonator banjo is a good goal, but a quality open-back or a resonator that isn't too heavy can work just as well while you learn.
When you see words like 'maple rim', 'tone ring', or 'Remo head', know that these affect the tone quality but you don't need to obsess over them yet. What matters more is whether the banjo stays in tune and is comfortable to play. 'Scale length' is simply the distance from the nut to the bridge; most banjos are 26.25 inches, and unless you have unusually small hands, it will be fine. A 'truss rod' is an adjustable metal rod in the neck that lets you correct bowing. Have it checked by a professional later if you can, but don't feel pressured to adjust it on day one.
As a beginner, expect your first weeks to be about building calluses on your fingertips and learning basic rolls (string patterns). You don't need a $1,000 banjo for that. You need an instrument that doesn't fight you. A well-set-up budget banjo is better than an expensive one that isn't set up. Look for customer comments like 'arrived in tune' and 'low action', those are beginner-friendly signs.
One thing to keep in mind is that no banjo is completely 'easy'. You will hit a learning curve, but a good beginner banjo keeps the curve from becoming a brick wall. If you can find a banjo in the $200-$400 range with geared tuners, a playable neck, and a decent setup, you'll be able to focus on playing rather than struggling with your instrument.