I am nico, I want to learn Japanese.

Watashi wa nico desu. Watashi wa shitai Manabu nihongono wo manabitai desu.

わたしはニコです。わたしはにほんごをまなびたいです。

Good job! I'd like to recommend you to remember the Japanese characters (Hiragana and Katakana) first. Enjoy learning and good luck!