Who can tell me some software sites for ubuntu, thanks!

You actually can use Synaptic Manager to download programs. Also there is a software market installed on most recent Ubuntu versions. Hopefully that helps.

Hmm. There are many softwares to use with ubuntu so it mainly depends on what you will be needing. It’s like windows. You only have what you need.
For example, if you want to use it for vector and bitmap imaging, you can use Inkscape and GIMP, respectively.

Pretty much all you need is the synaptic manager located on a branch on the top bar and you’ll be fine. :)