I downloaded the train.csv file from the link you posted. When I read it in and look at its structure, most of the columns are not numeric. Is this the data set you are working with?
Train <- read.csv("Train.csv")
str(Train)
'data.frame': 8068 obs. of 11 variables:
$ ID : int 462809 462643 466315 461735 462669 461319 460156 464347 465015 465176 ...
$ Gender : chr "Male" "Female" "Female" "Male" ...
$ Ever_Married : chr "No" "Yes" "Yes" "Yes" ...
$ Age : int 22 38 67 67 40 56 32 33 61 55 ...
$ Graduated : chr "No" "Yes" "Yes" "Yes" ...
$ Profession : chr "Healthcare" "Engineer" "Engineer" "Lawyer" ...
$ Work_Experience: num 1 NA 1 0 NA 0 1 1 0 1 ...
$ Spending_Score : chr "Low" "Average" "Low" "High" ...
$ Family_Size : num 4 3 1 2 6 2 3 3 3 4 ...
$ Var_1 : chr "Cat_4" "Cat_4" "Cat_6" "Cat_6" ...
$ Segmentation : chr "D" "A" "B" "B" ...