When you got you're PC didin't you get a CD with it ?
-Sound
My PC's MotherBoard is pretty raw. After doing an fdisk, and installing Windows, the sound driver must be installed off of a CD. Nothing you can do without the software. Look around for that CD you got with you're PC, and when you do, cast it into a safe or soemthing.
-Resolution ? (in this case i'm assuming you know little about this)
You say everything is really big and not just the text. Again without the video driver, you're PC's video resolution is probably running at 640x480 stock which is very large and not very sharp. Some PC's do this as it is reduced to a very low bit rate for colour too.
Right click you're desktop
Go to properties then go to settings
Set it to 800X600... or to whatever perferred resolution is availible to you. (Without the correct drivers, you're card will perform very poorly, and you'd be lucky to have 800x600 at the least.)
Again if you can get that CD and run it, you'd see the light that would guide you. You would see a list that says things like "Install sound driver"
In many cases the Mother Board (If it's anything like mine) will show it's model and logo just after the Bios when you start the machine. If you can't find the CD use that....("If it's anything like mine")