Ja, Herr. Germans would not typically say sir (Herr).
Gern Geschehen
Bitte sehr, mein Herr or short: bitte
"welcome" translates as "willkommen"
Welcome to Wolverhampton = Willkommen in Wolverhampton
In slang, you can say "no prob" or "no worries" as a casual way to respond to someone thanking you.
"Wilkommen in Austin."
In German it's Willkommen.
Gern geschehen
Willkommen in Gaming
Willkommen in Paisley
Bitte / Bitteschönbitte schön
G'dayThere is no specific Australian slang word for 'welcome'. G'day is a greeting, but does not mean 'welcome'.
Willkommen bei Facebook.
Willkommen - pronounced vill'kommen