Welcome to the forum.
Outdoors in the afternoon is going to be a heck of a lot easier for you with that camera
I agree, most point & shoot digitals will do much better in that situation than any other...however, there are still plenty of things that those cameras just can't do.
If you are thinking of getting a new digital camera, I would really suggest looking at the entry level DSLR models. The Canon Rebel XT or the Nikon D50 are the best ones. They are more expensive than a P&S digi-cam but they are 10 times the camera.
However, if you must, you can use what you have. As mentioned...practice, practice, practice.
Don't worry about a filter set, this is digital...the only filter you really need is a polarizer, which might be a good idea for outdoor shots.
Fill flash is not a kind of flash but a way to use your flash. Look it up and do some reading. If you have a camera with a hot-shoe, get an accessory flash and learn how to use it. The farther you get the flash from the lens, the better your photos will look.
If it's bright, you shouldn't need a monopod...it can tend to get in the way anyway.
Backup, backup, backup. Have two of everything, even if you have to beg borrow or steal. You can't just say sorry if your camera stops working or if you drop your flash. You have to be prepared for any number of problems that pop up.
Shooting a wedding can be tough...why do you think they charge so much? The standard advice is to convince them to hire someone with experience and then offer to shoot candids and other stuff. When it's all said and done, the photos will be more important than how the food tasted or how many flowers were there. This is not the area to skimp on. Having said that, if you think you can do it, then go for it. Research and practice as much as you can.
Good Luck.