You can use the process tab of the Cheat Engine to find the game value of the game in BlueStacks and then edit accordingly. Launch Cheat Engine and open the BlueStacks emulator.

Is Cheat Engine illegal?

No, Its not illegal.

Will BlueStacks hack my account?

The app itself is as secure as any open-source virtualization software out there, but won't do you any good if you execute malicious apps on it.