很遗憾的告诉你，你网上查到的各种改my.enf ，各种update，在新版MYSQL中，统统失效。
解决方法，如下：
1.
[root@yisu-5f735cb14d716 ~]# service mysqld start
Redirecting to /bin/systemctl start mysqld.service
[root@yisu-5f735cb14d716 ~]# mysql -v
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 8
Server version: 8.0.22
Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Reading history-file /root/.mysql_history
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
3.在尝试切换database的时候，mysql已经很友好的提示，使用alter user改密码：
mysql> use mysql;
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.
4.那我们就改吧。
mysql> alter user 'root'@'localhost' identified by 'Li234*&……F&%';
--------------
alter user 'root'@'localhost' identified b 'Li234*&……F&%'
--------------
Query OK, 0 rows affected (0.01 sec)
5.flush权限，结束
mysql> flush privileges;
--------------
flush privileges
--------------
Query OK, 0 rows affected (0.01 sec)
mysql> quit
Writing history-file /root/.mysql_history
Bye
6.登录测试。