Hehe, yeah...learning to speak Mandarin and learning to read Mandarin are completely different worlds. When I first got to China I knew the characters for stuff like chicken, pork, fish and veggies, so we'd try to stab at a semi-balanced meal and see how it turns out. The locals were always very amused and appreciative of us foreigner's attempts to speak Chinese though.
I'm sure you can get the greetings down...different people find it easier/harder to deal with the tones though. Whatever else, it'll be a fun challenge.