Most of the xp comes from the main questline and if you exclusively play that (ignoring side quests) it can be quite quick. In particular if you undertake ship battles in groups rather than soloing it speeds things up a lot; the main thing is to avoid fighting on deck during ship battles as that slows things up a lot.
Sidequests give you money, companion training points, nautical xp etc so they are important. If you complete all quests in each area then there are a lot of hours of gameplay.
It can be done within a week but you would have to devote every single minute you are awake to playing the game for a week and also requires a little bit of knowledge about the game which helps you progress through a little quicker. A more reasonable time frame for your first time through is about 3 weeks. If you only play a few hours a day and not everyday, then it could take anywhere from 2-3 months.
As you can see your playing habits determine how long it will take you and everyones are different.
Some tips if you wanna get try to get through a little quicker:
Like the previous poster mentioned, don't board ships. If you need to sink ships and your ship isn't strong enough to solo, then try changing reams until you find some help.
When you get quests that require you to kill a certain number of enemies, try changing realms to find others working on the same quest. Bigger mobs can complete the requirement in one battle where solo can take 3 or 4 battles. However, be sure to ask before joining other peoples battles.
Other than the first two suggestions I made above, solo the whole game. Everything else in the game goes so much faster solo.
Keep your friend list very limited. People constantly asking for help can really slow you down so by keeping your list limited and not adding every single person you sink a ship with or battle with will help keep you moving.
Although I don't recommend this your first time through, you can hold the space bar over the dialog when you have to talk to people to skip through it really fast.
I finished the game with a clean quest menu in approximately 2 weeks. Besides what was already mentioned, a very fast mount will make all the tedious running in between quests soo so much faster. I used a 1 day rental buffaloon most times (better if you can afford a perma mount). Herd all similar defeat and collect quests by talking to all NPCs with an exclamation point in a place. This way you will not be repeating battles from the same group of critters again and again
It depends on your playing style if you play for like 1 hour or 30 minutes .it took me about a year to finish and all I need to do is complete Aquila .see you in the spiral romantic rebbeca ivring level 65 .
If you play 8 hours a day... 1 week (gulity) if you play normally like 2 hours a day it can take a month or 2
I play about 4 hours a day (some days less) and it took me a month and a half to do Cool Ranch. I started playing Pirate101 again (I got a membership last year-i think- but I didn't play for a while) at the beginning of the summer. Around like June..... 3rd I think. And I'm now level 47. So, I don't think you could've completed the game in a week, playing 8 hours each day. Unless you had a max level helping you...... Then MAYBE.