There are many accesories that are both mandatory and not. Some make playing easier and aren't that expensive and others open a door to different cool sounds that you can emulate with the guitar.
Tuning guitars is fairly simple. It just depends on how many strings you have on that guitar. There are links for both acoustic and electric guitars, however once you watch the videos you will find that the tuning method is universal excluding the bass. Click on the links to view videos on how to tune them.
The objective of this website isn’t to pin your arm being your back to make you play the instrument. It is completely optional. However, there are many benefits to playing the guitar. Not only is it just fun in general, there are studies that show that playing the guitar helps with things like helping a person manage stress, improve memory, and improve their communication and motor skills all through music therapy. Unless you just don’t want to, there isn’t exactly a con to playing the guitar and it is definitely something that you should look into.