Life In 19x19

My color is Black.
May i have to correct the third question, it (probably) must be: "Wich is my level". Sorry but i speak very bad english.
Thank you for embedding the sgf file.

Hi,
i am a beginner player and this is probably the first game i win without any suggestion.
What do you think about it?
What errors i have done?
What is my level?
I can start to play in a 19*19 board?
Thank you.
(I apologize for my bad english.)