While it is really important to put a lot of thought and consideration into buying your first guitar, it is equally important to maintain it by buying the appropriate guitar accessories. A guitar like almost everything else in this universe is as good as the sum of its parts, and its parts (like strings, steel or nylon strings?) are many. So, if you are dedicated and passionate about learning this style of art, it is imperative that you should invest some amount of money into taking care of your beloved guitar.
Just like strings play an important part in the anatomy of an acoustic guitar, there are other parts and accessories that play a similar role for electric guitars and can influence a great deal the kind of music the guitar produces. If you are considering rocking genres like blues, metal etc, and have an electric guitar, then the investment should definitely go into an accessory like an overdrive pedal. The overdrive pedal apart from adding extra boost smooths out any sound distortion that may arise allowing you to play like a true rock star! On the other hand if you wish to create a distinct tonality to your sounds then a compressor pedal will do the trick.
No matter what accessory you choose, you can realize its full potential only if you have your music sorted in your head. You need to be very thorough about what you want to play and how want to play and only then can you make a fully informed choice to support your investment.