How to fit a curve into a set of data if the data appears to be non-linear and messy?

[Robertmessi]

I need to quantify the relationship between the y-axis and x-axis, but looking at the data it is definitely right skewed and not normally distributed. I have no idea where to start in this case

 

[HallsofIvy]

Start by using a function that is NOT linear but has a mean or mode near low x.

 

[Deleted member 4993]

I need to quantify the relationship between the y-axis and x-axis, but looking at the data it is definitely right skewed and not normally distributed. I have no idea where to start in this case

View attachment 22197

I would first try log-normal distribution

 

[Robertmessi]

Thanks I hope to learn more about fitting. Anyone can suggest a reference?