How to calculate incidence and prevalence rate?



I would like to ask,
Could you explain more closely the incidence rate and the prevalence rate of these two, the calculation of the description or provide the formula?

Because our country has data on all ages and gender in diseases,
So I want to figure out the incidence rate and the prevalence rate of different diseases by sex and age in our country.
Before I count, women 35-39 mortality, lung cancer, incidence rate,
I use two different methods:

The first method:
The number of female lung cancer deaths at 35-39 was divided by the total female population aged 35-39

The second method:
To see the mortality rate of lung cancer per 100 000 population of 35 ~ 39 years old women

Regardless of the method used to calculate the results are different with the data provided by BENMAP.

Howard Lan