I have data with customer personal information and customer transaction. I cannot figure out how to use the data for training my model? Customer information attributes:
ID
Age
Gender
State etc

Customer transaction
ID 
Store ID
No of items bought 
State etc

Store info
Store ID
State
Daily revenue
Store size etc

I want to predict if customer will buy at a particular store or not/
So can I have the train data with suppose 5 different stores for every customer where the customer shops and then predict in other store?
Yes you can. 
On the files you have mentioned above i guess, you have merge the data. But keep in mind to remove redundant columns. 
After that you have to :
* check if there are any missing values or null values
* find the relation between one independent variable to other independent variable
* find the relation between independent variable and the dependent variable

Then split the data into train set and test data and apply your model