I'm glad it worked
You should now write a boot script so that those commands get run automatically each time you start your computer (otherwise you would have to run them manually after each reboot). To write the script, first type:
A blank file will open. Add these lines to it:
sudo gedit /etc/init.d/wifi-fix.sh
Then save and close the file.
ifconfig wlan0 up
Now run this so that the script will get run at boot:
That should allow you to reboot your computer and have your wireless going with no problems. Let me know if you have any more trouble; otherwise, enjoy Ubuntu!
chmod +x wifi-fix.sh
Also as for sound: I don't know very much about sound on Linux myself, but a good place to start if you have problems is the community-documentation guide to sound troubleshooting.