I'll also explain the steps here to make it easier for people who aren't familiar with cheat engine (like me yesterday):
Basically, you install Cheat Engine (you might need to disable your antivirus for it to work), go through the tutorial if you aren't familiar with the software, then you have to get enough points to afford one thing in the shop (at least 500), open Cheat Engine, link CE to the game (explained in the tutorial), go to the shop, enter the amount of points you have in the value input, press first scan, buy something in the shop, click next scan, put your new points value in, then a couple addresses should show up, change them all to a big value (to buy everything, you'll need about 7000), then when one of them works, you'll see your points have increase ingame (automatic, you won't need to restart your game before seeing it).