will a simple lighter be enough to burn it?
Just google "how to start charcoal grill" or something as that'll give you a good explanation. A chimney starter and tumbleweed style fire starters are very useful as you can fill the chimney(s) with charcoal, put the fire starter underneath, and light it with a lighter and It should catch pretty easily.
if burnt in an open area like the middle of the woods would others see flames/smoke or smell it?
Honestly location was the toughest part of this for me and honestly, only you can make a guess at that because we don't know the specifics of what "the middle of the woods" is to you, or how many people will be there.
do you need a lot of charcoal or are a few enough?
The amount of charcoal you need depends on the size of your space. Bigger space needs more charcoal. More charcoal in a smaller space can't really "hurt" as it usually means higher concentration of carbon monoxide quicker.
does each individual piece need to be burnt? Does the type of charcoal matter?
Wait until your charcoal is obviously gray/white and glowing, and the white smoke has stopped. And yes, the type matters. Use high-quality briquettes or lump charcoal. People have done it with briquettes of course, but do research and don't get the cheap ones as they can have additives that cause a very strange smell, which is what deterred me from going through with my attempt.
Does the charcoal need to be mixed with something else?
Not sure entirely what you mean by "something else" but no. Not even lighter fluid. Adding anything other than charcoal means potential for more fumes/smells/smoke that you don't want. That's what happened to me.
Overall, please do look at all the megathreads/advice threads on charcoal because they do actually get very specific. Think critically about everything you read, though, including this, because not everyone is right.