Removing a User without deleting data on iCloud

Go to www.icloud.com in your web browser and login with you real Apple ID user account. That will show you what is "in" iCloud. If your data is there then deleting the test user wouldn't change that.

Before deleting a corrupted account in system preferences > users and groups you must create a new test user account .

HOW TO SET UP A NEW TEST USER ACCOUNT 

Before creating a new test user account you must have iCloud Keychain verification code in your records , if it is not with you create a new code .

( a ) Open system preferences > iCloud > the box for keychain is checked , click on options , click on change security code .

( b ) Click on security code > enter new code in the fields and click on next , you have to enter the new code for the second time and click on next .

In the next window the country code is written , enter your trusted mobile number …….and click on done .

Again enter your Apple ID password to update your account settings and click on ok , hence the code is changed , so write down this code in a safe place .

Then follow the upcoming steps -

Create a new user account in users and groups by clicking on plus sign , name an account and enter its password .

Take cursor on apple logo and log out from your old user account and then enter the credentials name and password on the screen of your new user account .

( a )The window is showing data and privacy , click on continue and sign in with your Apple ID ( fill up the credentials ) and click on continue .

( b ) Again enter your Apple ID and password and click on continue .

( c ) A prompt will appear on the screen use two factor authentication ( its optional you can uncheck the box and click on continue ) .

( d ) A pop up window will appear do not upgrade Apple ID security and upgrade iCloud security , so click on do not upgrade .

( e ) A small circle will be rotating , setting up account will be shown , wait for a while and options will be shown would you like to set up iCloud Keychain ( 1 ) set up iCloud Keychain ( 2 ) set up later , you can click on set up later and click on continue .

( f ) A window will appear showing enable ask Siri , keep the box checked and click on continue .

( g ) Another window will appear all your files in iCloud stores files from documents and desktop in iCloud Drive , so check the box of it and click on continue .It will show setting up your Mac , three right check marks will be shown .

( h ) Open system preferences and click on accessibility > trackpad options , check the boxes of scrolling with inertia and enable dragging with three finger drag and click on ok ( as drag and drop feature always help a user in every way ) .

( I ) Again in the system preferences > click on I cloud you will see the box of keychain is unchecked , so check the box of it after a while a prompt will appear enter you Apple ID password to set up iCloud Keychain so fill up the password and click on ok .

( j ) Again a pop up window will appear to set up iCloud keychain on this Mac , request approval from one of your other devices using iCloud Keychain .( 1 ) use code ( 2 ) cancel ( 3 ) request approval , so click on use code .

( k ) Wait for a while , nothing will appear on the screen after that a window will appear enter your iCloud security code , so after entering it click on next .

( l) An sms will come to the trusted mobile so enter the code and click on ok and you will notice in front of keychain setting up and a small circle is rotating , the box of keychain will get checked .

( m) On the top right corner of the screen a small notification will appear google password required ( in your case it depends which sevices are being used yahoo , hotmail or other ) .

( n ) Enter your gmail password and click on next , finally iCloud Keychain is set up in the new user account you can open mail application and click on get mail icon all mails will start downloading from the server .

( o ) Open notes application and click on continue all notes data saved in iCloud and in all google will start downloading and it will take time to download ( high network speed is essential ) .

( p ) Then open calendar and click on continue , click on view and show calendar list .

If you want to transfer pictures , movies , music , downloads contents from the home folder of first user account to the second user account .

Open pictures and press command and info change the permissions to read only the folder pictures will be unlocked , them drag and drop the folder on the desktop automatically you can view the contents of pictures in the second user account .

If you had created two admin account in users and groups the second one is corrupted , deleting it https://support.apple.com/en-in/guide/mac-help/mchlp1557/10.14/mac/10.14

Will not affect iCloud data ( make sure in system preferences > iCloud , all the boxes for safari , keychain , notes , calendars ....are checked .

Not necessary if you had a single admin account in Mac and that is corrupted , if you create a new admin account it might act as corrupted as system files are corrupted .