hello skyrim'ers! i just killed my second dragon after retrying for 2 hours and with the aid of some mammoths xD but i collected the soul before i realised i dont have any words in my vocabulary to unlock it with, will i automatically unlock the next shout i learn or will that kill just be void?

It wont be void.

Of course. You have his soul within you, now you will learn a word to use that soul's power.

thank you!

Neither will happen actually. The souls will be stored, and you'll have to manually unlock any further words your learn. That prevents you from worrying about learning the wrong word first and "wasting" the soul.

so it actually has to be the first word out of the 3 to work?

Hehehe my first Dragon battle used up all my potions, almost killed me a few times, but it was epic.

Potential Spoiler:

This one Falmer boss with a Dwemer centurion keeps killing me Level 6 already. Keep going at him or try later?