this is my first time to try .htaccess
this is what i want.
example.com/account/blitzen12 -> example.com/account/index.php?id=10&name=blitzen1
The "10" or the id, isn't part of the URL:
example.com/account/blitzen12
So you can't rewrite it into another URL, can't pull it out of thin air. You'll either need to just serve the page without an "id" (and pull it out of the database using the "name") or embed it in the URL without the query string, something like:
example.com/account/10/blitzen12
then you'd be able to rewrite it using:
Options +FollowSymLinks
RewriteEngine On
RewriteRule ^account/([0-9]+)/(.*)$ ./account/index.php?page=account&id=$1&name=$2 [L,NC]