To scan for viruses on Linux, you'd us
clamav. You can install it from the repositories using the software center.
If you're new to Linux, this is the perfect time to try out the command line interface, because it works well, and it's hard to screw anything up.
If you're feeling up to it, open a teminal window by typing
In that window, type
sudo apt-get install clamav. This will tell the computer that a "super user" is telling it to install the clamav virus scanning software. It will ask for your password.
Now that you've installed the software, you need to update the files that it uses to identify viruses. You should type
sudo freshclam. Your computer will know you're a super user because you just typed in your password a few seconds ago.
When all is done, you're ready to scan. If you'd like to scan your home directory (all your user files), you'd type something like
clamscan --remove=yes -i -r ~/
This calls on clamscan to remove any virus it finds, show you only infected files, to act recursively by running through every subdirectory of you home directory. ~/ is shorthand for your home directory. You might want to run it without the --remove just to see what it finds first.
if you were to type
man clamscan you'd see a list of options. As I said, this is a great place to start using the command line.