Many data analyzes use a theory that assumes a normal distribution. I think it's often okay to use it without worrying about whether it's really a normal distribution, but sometimes I want to check.
An example of using R is as follows. (The following is copy-paste and can be used as it is. In this example, it is assumed that the folder named "Rtest" on the C drive contains data with the name "Data.csv". It is assumed that the column name "X" contains a numerical value.)
setwd("C:/Rtest")
Data <- read.csv("Data.csv", header=T)
shapiro.test(x=Data$X)