I have a PowerShot A75 and I dont think I have a shutter speed option on it.
What is a SLR?
Anna
Here's some info about your camera. I recommend you read the manual because you'll find it's a very capable camera. This link is basically a list of features the A75 has. Your manual will have much more info:
http://www.dpreview.com/reviews/specs/Canon/canon_a75.asp
Your camera does have aperture priority and Shutter speed priority settings. It also has a variable ISO, so freezing action is well within your cameras capabilities, so long as you take control of it instead of letting it make all the decisions.
If it was up to me and I was using your camera, I'd put it to aperture priority (this is where you choose the aperture and the camera picks the nessessary shutter speed) and use the camera wide open (the smallest numbered aperture value - 2.8 in your case). In darker situations you can then jack the ISO from 50 to 100, 200 or 400.
Basically, don't bother spending money on a new camera because yours will do exactly what you need it to, so long as you learn how to use some of the features. I would also recommend going to the library and borrowing a basic book on digital photography so you know what you need to adjust on your camera to get effects you desire with your camera.
As for an SLR, it stands for Single Lens Reflex camera. The advantage to an SLR is you can change lenses and when you're looking in the viewfinder, you're seeing exactly what the photo is that you're going to take (though that's less of a problem with digital compacts when you use the LCD), including making sure your shot is perfectly in focus. The quality of photos is much better - especially at higher ISOs and performance-wise, they're leaps and bounds ahead of Point'n'shoots. You also have a lot more info available to you before you take the shot, like what your aperture and shutterspeed is, where you're focusing to name a couple. The main downside to SLRs is even the smallest of them is very big compared to most compact cameras and if you're new to photography, all the adjustments can become confusing until you learn what you're doing.
Anyways, if you sayed awake for all of that, hopefully you'll be able to make your camera work they way you want it too.