UPDATE:
I've managed to find the very root cause of all the errors and troubles from the very beginning!
The reason why the classpath error occured back then was due to Windows 10 Security Defender update which automatically turns on a new feature called "Controlled folder access". What it does is regulate and monitor what applications and services changes a protected folder and when a certain app/service is not recognize or allowed by the feature, it blocks it, thus, preventing the editing of IDE on the source files. Alongside those is the effect on gradle which I've encountered where it stops the gradle from further downloading the dependencies regardless of how many times you try. SOLUTION:
I've tried including the java.exe to the whitelist so they'll be able to edit the folder and add the necessary dependencies but it does not work so cross that one out!
To have it completely working, you have to turn the feature off by following these steps:
Open your "Windows Defender Security Center".
Click on "Virus & threat protection".
Click on "Virus & threat protection".
Scroll to the bottom and click "Controlled folder access".
Turn off the feature.
Hope this helps people who encountered same error as me on Windows 10.