It depends on your skill level. For beginners, it can be a bit challenging as it has some melodic runs and chord changes. But with practice, it can be mastered.
Another option is to ask in some piano - related forums or groups. Musicians there are usually quite helpful. They might have the piano sheet you are looking for or can give you some good suggestions on where to find it.
You could search on YouTube. Sometimes musicians upload videos with links to the sheet music for the pieces they play. Or, ask at your local music school. They might have recommendations or even have some sheet music available for borrowing.
There are several factors that can make it either difficult or not so difficult. The tempo of 'Fiction' can be a challenge as it might require quick finger movements. Also, the dynamics and the use of different musical notations in the sheet music can add to the complexity. However, with regular practice, breaking the piece into smaller sections, and gradually building up your skills, it can become more manageable even for those who are not at an advanced level.
You can try searching on some free sheet music websites like 8notes.com or Mutopia.org. Sometimes, composers or musicians also share their arrangements for free on their personal blogs or social media.
You could also check with local music stores. Sometimes they have a selection of sheet music available for purchase. Or, search on online marketplaces like eBay or Amazon.
The best places to look for that piano sheet could be YouTube. Sometimes, people upload videos with links to the sheet music in the description. Or, try visiting your local music store. They might have it or be able to order it for you.
You can try looking on specialized sheet music websites. Some popular ones are 8notes.com and SheetMusicPlus.com. They often have a wide range of music available for download.