what are GFI outlets?
GFI, or more accurately, GFCI stands for Ground Fault Interrupted Circuit. It is a special receptacle that will trip if it senses trouble in the circuit. It can be wired to protect all devices "down stream" of the circuit as well. If a GFCI receptacle is tripping, it's either doing so because of an issue in the circuit or in the device itself.
I’m not sure what electrical conduit is
Electrical conduit is just that. A conduit through which electrical wires/cables are run. They come in metal and PVC. There are benders for the metal conduit and the PVC can be purchased with elbows and adapter to get the wires into and out of the electric boxes. Once dry fitted, all the PVC is cemented together to form a water-proof tube through which all the wires are protected.
If you are not comfortable or familiar with doing electrical work, you certainly want to hire a licensed electrician.
If you are a good DIYer and understand the basics of the NEC (National Electric Code) or the code specific for your area, you can do the work yourself and have it inspected by a licensed electric inspector.