Creating transaction using php

Hi there friends! Can anybody help me with my project? I have to develop a Loan System using php. I don't have any background with this yet so i need your help.
 
DATABASE: Loan
TABLES:
Member: member_no, username, name
 
Password: username, password, category //here i am storing the data for login and the category will be admin or member.
 
Product: product_no, product_name, product_type, description, price
 
Transaction: member_no, product_no, no_of_payments //in here i am storing the transactions of every members. it's like the master list of all the member's transaction.
 
Transaction_2: member_no, product_no, payment, date //in here, i am storing every member's transaction for members' to view their account.
 

I have made my login and registration page. But i can't do the transaction. Can anybody help me with this? You're comments and suggestions are very much appreciated!