It's straightforward and a good first project IMO; partly electrical, partly structural. The Lowrance instructions will walk you through it, just take your time. The key steps are determining the mounting locations and sealing any holes that you drill into the hull. There's not much else to screw up. Tools needed would be a drill, a set of drill bits, screwdriver, some sealant (probably specified in the instructions, probably going to be RTV silicone or 3m 5200/4200), and maybe some zip ties to secure the wiring run back to the head unit. You could probably get all of that at Harbor Freight for under 50 bucks.

The power wiring is also easy, just 2 wires, + and -. They go to their respective busses (near the battery or under the console perhaps). You could simply tighten down the terminal screws onto the bare wires or upgrade and crimp on some fork style terminals.