How to change wordpress adminstrator user ‘s ID from 1 to 0?

The MySQL table that stores the user data wp_users have an autoincrement on the primary key ID. The database will handle it automatically to avoid duplicated values and the minimal value is 1.

There is nothing you can do about it.
Here is the WP tables shema if you want to have a look https://codex.wordpress.org/Database_Description#Table:_wp_users

There is no such thing as admin/client distinction in the user storage.
What you might want to do is create a new user for your admin (its ID would be 2) and then rename the first user and set the right role for your client.
Of course, the next user will have ID 3 and so on…