To create an user account you will need security code and company code handy provided during company registration. These two code is for verification & identification purpose. You can obtain this code from your company administrator. Create an account from here:
Register User Account.
On successful registration you will receive mail for email verification, which is mandatory to complete the registration.
Company administrator need to activate the account by navigating to Settings-->Team/Account Activation menu. List of new registered teammates will be shown their which need to be activated to enable WMS access to account.