The best and the most accessible tool to use for finance is Excel. Of course, you have a lot of financial apps and even Personal Finance software now to help you understand and manage your finances, however the most flexibility in what you can do and change, so that it is personalized to your needs, in a simple old Excel.
When you don’t have Microsoft software and unwilling to pay for it, you can consider free alternatives, such as Google Sheets or available for download free or cheaper Microsoft alternatives. Mac users also can use Numbers instead of Excel.
For the expenses what is important is to become really diligent in recording all of them immediately as they take place, or at least on the same day for some time. Later you will know what you spend on and will easily recall all the categories, however before that you need to get into the habit of analyzing your current expenses in all the details.
Let’s get down to the Expense Journal creation then?