I have never played "Secret of Monkey Island" 1 or 2 so I was wondering if I can play this one without any background knowledge of those two previous games?

That's where I started, I'd say you'll still enjoy yourself.

the first 2 games tie in with the story a bit, but other than that...you'll just miss some in-jokes and characters/events from previous games. So it's not that big a deal.

OK sounds good. As long as it won't prevent me from making it through the game then that's fine. Perhaps I'll play the first two after this one.  
 
Cheers.

You´ll miss out on characters and references that heighten the game experience but its not vital for your enjoyment of the game. 
You really should not miss the other two tho. Great great games.      
The best way would really be to start out with the recent remake of MI1, then try to get your hands on the 2nd one, but if you cant, go on to the third one. 
As a big fan I really recommend playing the first one before you go for MI3.

I played curse before I played the first two, an was fine but with Secret of Monkey Island Special Edition being out, I'd suggest playing that first.