Help! coming from a freshman!

[hellotree]

Hi, Everyone!
I got some problems with my system.
I'm going to try the Linux. (I think there is a lot of fun.) I haven't any experience of Linux.
Yesterday, I finished the install of the system. And it's an English version.
Here I have some problems to consult you:
1, there is no sound of my PC. is it necessary to install the driver for the sound card?
2, how to input Chinese and new input method into the system?
I found some commands in the internet. But I don't know how and where shall I input them.
3, During the install process, I just have one partition for Linux. No swap.
4, The RAM of my PC is 2*2=4G. just now, I just fond 3.2G from the 'system monitor'. Can you give me an explanation? (the Ubuntu version is 32bit, i.e. - x86)

Thank you very much!

[Goomy]

http://wiki.ubuntu.org.cn/Qref
在这个链接里找你对应的版本设置

[hellotree]

Thank you!
I'm reading it now.

another question:
Is it necessary to use an Anti-Virus or Firewall in Linux?

[Goomy]

no need