As a foreign fan who goes to one game per season I recommend you not to be too shy singing all the songs and be part of the community. At my first visit to the Lane (2007 May vs Blackburn) I thought it's just the privilege of the local fans and ST holders and I'm just a visitor (however when Defoe equalized we hugged each other with the unknown bloke next to me like best friends), but later when I was drunk enough to behave like a supporter really should, it became the best sport experience of my life.
And whatever happens tomorrow, after the game go to a local pub. I don't know how old your son is, but you both will definitely love it. I went to J.J. Moon's following the United fiasco in Januray, Spurs shirts everywhere, the pub filled with proper fans and the chants were so loud that my beer was moving on the table. These moments get you even closer to this great club.
In general the main difference I see between locals and foreign fans is the feeling or sentiment against arch rivals. All the years I spent among other clubs' fans, the debates on the web or in real life conversations, the way they talked to me or about Spurs, it all directed me to the same way as anyone who's got lilywhite blud, but in this case I have to agree with r-u-s-x and it's a bit odd when people fuming over WestHam 1000 miles away from London. I was living close to Fulham Broadway, spent there almost two years, those phuckers celebrated their PL trophy in front of my flat, but still, it's not in my bones. I don't know what this thing really means, Millwall fans didn't attack my relatives 30 years ago, the stadium occupied by WestHam was not built from my tax, I called the gooners homless nomad bastards without the ability to spot Woolwich on the map. Even calling scousers bindippers or lauging at the unemployed jokes would be beyond belief as I'd cross my fingers for the average salary over there (sad but true).
Don't get me wrong, I'm counting the minutes in the days before an NLD and getting extremely nervous till the kick-off, like all of you, but you have to be a born and raised English Spurs fan to have it in your bones.
And I really do hope other foreign fans don't take it as offence against their loyalty for Spurs.