A way to keep track of my expenses

I been struggling with my monthly budget for years. 
I know what's the point of a budget if I don't follow it. Lol
So I decide to track my expenses starting next week.
You know every time I spend or make a deposit I will write it down andsave it. I the end of the month I'll have an idea of where all my money goes.
As of now I know for a fact how much I spend on my bills. But not the extras.
Also next month I will start a challenge to save money every month. The challenge name is "the 52 weeks challenge".
But for now I had to dig in my supply bag to found a place to enter my expenses. 
I will be using this weekly note pad from target.
I usually use it to write my weekly menu plan and my to-do list if I need more space.