Pick a simple goal or idea for your AddOn. It's often a good idea to just make an AddOn that only opens a window or prints a message to get started, especially when everything is new for you. After that works the way it should, and you have learned everything necessary to make an AddOn work at all, you can move on to adding one piece at a time toward your goals. Writting software in general is often a never ending process because you can always think of something new to add or improve.
Also note that power leveling is sometimes used to refer to paying someone else to level your character to cap as fast as possible (i.e. they power level for you); a distinction used by Blizzard is to refer to the paid leveling as "power leveling service." This behavior is against Blizzard's Terms of Service. Power leveling yourself, which this article covers, is perfectly acceptable.
Obtain your heirloom rings. Ghost Pirate Rings can be obtained via Shipyard missions. You can equip one ring from this category. A Dread Pirate Ring can be obtained via placing at least second in the weekly Stranglethorn Fishing Extravaganza, which on many realms is a very competitive event. Note that to obtain the Ghost Pirate Rings, you will need a max level character with a garrison of at least level 3. You you will also have to develop your Shipyard to the appropriate level to receive the mission. Your other heirloom gear will still give you a big boost if you choose not to go for these.