Macbook air & macbook pro non retina

Hi everyone,

Before buying Macbook air 13' 128GB 8GB RAM, I took people suggestion that which MacBook air I should go for.. where my budget matched to only MacBook air.. coz i wanted to learn music.. and air has inbuilt garageband which is good for learners.. but as of now I am left with only 87GB of space in my MacBook air after installing everything inclusive garageband all music tools which took 14GB approox ...

what is making me concern here that is 87GB space is fine to create garageband project and move those files to a hard disk .. is that sufficient for me to do so. with remaining 87GB of space..

or i was wrong buying MacBook air 13' 128GB

or I should have bought MacBook pro non retina which is even inexpensive than air.. and we can use garageband, logic pro x very easily... because it has 500GB of space as well..

seems i have taken wrong decisions buying MacBook air...

could you tell am i right or wrong... with sensible reasons..