Random Sampling from a dataset

I have financial data with values like: "Volume", "Profit/Loss", "Cost", etc

Now, it is safe to assume that every record in this data set is a "realization" or outcome of a single random variable, hence we may model this dataset as a set of iid random variables.

Now, I want to leverage this data set to model the underlying distribution of this random variable.

Can anyone point me in the right direction?