The template won't work correctly unless you specify your username; so add the following to the new user's talk page:
{{subst:User:Ukexpat/welcome1|Your username here}}
Replacing "Your username here" with your actual username.
Also, you may add an additional comment by adding the following to the new user's talk page:
{{subst:User:Ukexpat/welcome1|Your username here|Your additional comment here}}
Replacing "Your username here" with your actual username and "Your additional comment here" with your actual additional comment.
Note: The template won't work correctly if you do not subst: it.