How to draw the Greek letter $\xi$ [closed]

One way, which I don't personally use but which works all the same, is to draw a lower-case $e$ (or even $\varepsilon$ I guess) and, without taking your pen off the paper, draw a lower-case $s$ directly underneath it. It certainly doesn't say anything about the difficulty level of the topic involved.

Alternatively...

should I draw an S with some curly C on top of it?

No, it is better to draw it in one stroke. Start from the end of the little thing top left and follow continuously the curve until the little thing bottom right. Twice your pen should stop and go backwards, as is done once when drawing $\varepsilon$.

Do we use this letter in order to imply the level of difficulty in the topic it appeared?

Not that I am aware of, but $\xi$ is often used to correspond to $x$, like one would use $\alpha$, $\beta$ and $\gamma$ to correspond to $a$, $b$ and $c$.

Could you please (...) help me to like this letter?

Sorry but no I could not. I find it beautiful, you do not, end of story.