Modify this database and clone a simple table in html

I have a website and all what I need in it is to add certain columns in its database. What the table does for me is it stores records each and everyday and then it displays the records in a table in my html page. The thing is, it only shows record for 2 days, I want it to show record for 30 days. After 2 days pass, it replaces the recorded data so I always have 2 days data only. I want 30 days data to be available and displayed in a table. Next, I want you to do is copy the system of recording data. And make a 2nd system in which there will be only 1 difference that the data shall be used to calculate something else instead of the first one. The first one calculates cash, while 2nd will calculate credits. Third which is the last thing, I want to display the table of the copied system i.e. 2nd system which you copied. There is a table that shows the data from 1st system but I also want to show the data from 2nd system. Simplifying: Objective 1: Record data for 30 days instead of 2 days Objective 2: Make table display data for 30 days instead of 2 days Objective 3: Copy the 1st system which is used for recording data with minor difference Objective 4: Make another table which displays 2nd system data instead of first one (30 days)