The bassoon is one of the larger orchestral woodwind instruments, heavy and a little bulky to transport. For this reason and the amount of physical energy/lung capacity required to play it, most beginners start at an older age. Usually children would learn a small instrument while small and only start bassoon once they have developed enough physically, around 11-12 years.
However, there is a smaller instrument available called the mini bassoon which is a good option for younger beginners.
The bassoon is a double reed instrument, the sound is generated by the vibration of two reeds bound together, known simply as a reed. The player puts the reed in their mouth, forms a seal with their lips and blows through the reed. Learning to control this process is a key part of the basics of bassoon. Reeds are notoriously unpredictable, and you should not expect every reed you buy to be as good as the last one as they are a natural product and very variable.
The bassoon is a bass instrument, reading bass clef so if the beginner has learner an instrument such as the flute first, which is in treble clef, they will need to learn the bass clef.
As bassoons are expensive instruments, it is common to buy them on finance.