Space/storage

Buy an external External Hard Disk and move your large libraries onto the External Hard Disk. For most users, what tends to take up the most space is their media (photos, movies and music) so if you move those libraries to the External Hard Disk that can help free up space on the internal storage. Apple explains in the link below how to move your Photos library, the same holds true for music and movies.

Move your Photos library to save space on your Mac

Also, next time, please buy a Mac with more than the minimum of available storage.

Apple will trade it the computer however don't expect to get near what you paid for it. Apple has a 2 week return period assuming you bought the computer directly from Apple. As your machine is months old, just get the External Hard Disk route and move on. If you bought the machine from an Apple reseller, contact the reseller however I don't think they will allow you to swap it.

Your welcome and best of luck.