Do you basically like the bike and just want to change a few things or are you looking for something different? The frame is nice enough but upgrading won't really change how it rides. If for example you want better shifting, or a different gear range, upgrading may help. Upgrades won't make the bike faster, though tires could be an exception to that.

You can upgrade the components but unless you do the work yourself (and maybe even if you do), it may be cheaper to sell this bike and get another one depending on how much you want to change.