First notebook entry: Introducing myself

你好!
我想学习汉语! 学汉语是我的乐趣! 但我觉得学习汉字字符是件很困难的事. (?)

First notebook entry: Introducing myself

你好!
我学习汉语! 汉语是乐趣! 但 学习字符是困难的. (?)

我正在学习汉语，这是我的乐趣！但学习汉字是困难的。

I am learning Chinese recently, which is my hobby. But it is really hard for me to learn charactors.(My English is not very good, but I guess this is what you want to say. At the beginning of your study, I suggest you write Chinese lines right below English lines, so that people who help you with your composition can understand you very well, and you can compare two languages by that way.)

学习汉语 is the thing that now you keep doing, so when you describe it, you should use "正在" before it as "be doing" form in English.

汉语是乐趣 means "Chinese language is interest/hobby", so you used wrong subject. You should say "Learning Chinese alnguage is MY interest", which is translated to Chinese as "学习汉语是我的乐趣". But in the first sentence, you already used "学习汉语", so in the second clause you should use pronoun, "它/这", to replace "学习汉语".

In Chinese language system, we don't have the concept of "字符". Instead, charactors(汉字) is the fundamental unit. 

First notebook entry: Introducing myself

你好!
我在学习汉语! 学习汉语是我的乐趣! 但 学习写汉字字符是困难的. (?)