can not login to a newly created site (multisite enabled)

Following this manuel https://premium.wpmudev.org/manuals/wpmu-manual-2/creating-a-network-to-enable-wordpress-multisite/#manual-contents
I enabled multisite and network under one wordpress installation.
I created a site and hit start to login, but it send me to an inccorent link like this:
mydomain.com/site-name/wp-admin
Can not be accessed with proper login info.
Help will be very much appreciated.
thanks