As far as I know, kennen is to know somebody and lernen means to learn Then why do you use kennenzulernen to say nice to meet?
kennen = to know, lernen = to learn
The verb kennenlernen, however, has the meaning to meet, even though it looks like it is a combination of kennen and lernen (which is definitely its origin, but it is used as one word today).
The original meaning can be guessed from the word by word translation
Schön, Sie kennen zu lernen (or kennenzulernen)
Nice to learn/to get to know you
The actual translation, however, is simply Nice to meet you.
PS: kennenzulernen is a so called "erweiterter Infititiv". You can see this in other verbs, too. Examples:
Es ist Zeit, auszusteigen (aus dem Zug)
It's time to get off (the train)
Bitte denke daran, die Tür abzuschließen
Please remember to lock the door
This is also called Infinitiv mit "zu". Examples:
aussteigen => auszusteigen
weggehen => wegzugehen
stehen => zu stehen