Welcome. :-)
Check
this link Which one of the Commodore machines is it?
We can help you better if we know exactly what machine you've got. It sounds like you may have an A3000T, which is a great machine.
After you've identified the machine, you'll probably want to pop the cover off to see what hardware you've got inside. If it is a big box Amiga (as opposed to a computer-keyboard-all-in-one unit), there's a very good chance that the battery keeping track of the onboard clock is leaking (the big, blue barrel-shaped thing will have fuzz or blue goo around it). If that's the case, report back here and we'll point you to some starting points for getting rid of it safely.
Oh, since you're new to the Amiga, be sure to remember the most important rule: NEVER plug/unplug ANYTHING from the system while it is on! Circuitry inside can (and likely will) break!
Have fun with it! The Amiga is a fantastic hobby/tweaking machine! It's also fine for contemporary serious work if you don't mind about incompatibility with most file formats on PCs and Macs.
Don't hesitate to ask for more help!
