How to connect properly and set up my laravel .env file using the credential of phpmyadmin

I have problem to my local laravel project and localhost phpmyadmin, this morning my root password of my phpmyadmin is not working and I don’t why it not work because I used this account for along time ago and now it gives an error of this Access denied for user ‘root’@’localhost’ (using password: YES)

So right now I decided to create new account on mysql and I create user as admin and password as admin4321 and well it work.

So right now my .env file look like this.

APP_NAME=Laravel
APP_ENV=production
APP_KEY=base64:ALMV1rEQL49GJWdydqdEiUGmSnrRFXHjFgrNxNX5iWM=
APP_DEBUG=true
APP_URL=http://localhost

LOG_CHANNEL=stack

DB_CONNECTION=mysql
DB_HOST=localhost
DB_PORT=3306
DB_DATABASE=file_db 
DB_USERNAME=admin
DB_PASSWORD=admin4321

BROADCAST_DRIVER=log
CACHE_DRIVER=file
SESSION_DRIVER=file
SESSION_LIFETIME=120
QUEUE_DRIVER=sync

REDIS_HOST=localhost
REDIS_PASSWORD=null
REDIS_PORT=6379

MAIL_DRIVER=smtp
MAIL_HOST=smtp.gmail.com
MAIL_PORT=587
[email protected]   
MAIL_PASSWORD=hiflyer123
MAIL_ENCRYPTION=tls

PUSHER_APP_ID=
PUSHER_APP_KEY=
PUSHER_APP_SECRET=
PUSHER_APP_CLUSTER=mt1

MIX_PUSHER_APP_KEY="${PUSHER_APP_KEY}"
MIX_PUSHER_APP_CLUSTER="${PUSHER_APP_CLUSTER}"



NOCAPTCHA_SECRET=6LeSDW8UAAAAAGbsUdQnZnQSc9yIlD-mP-XPGDW0
NOCAPTCHA_SITEKEY=6LeSDW8UAAAAAB5rrfbBsYx7Sa65-6sL9TC_-mMb

So now when I login my auth account in laravel it shows this. and all data from database is not shown in my website.

     Symfony  Component  Debug  Exception  FatalThrowableError (E_ERROR)
Class 'IlluminateDatabaseMySqlConnection' not found