Making space on a hard drive can be challenging, especially when you are working with a smaller drive to begin with.  What makes matters worse, is sometimes your drive is indexed in correctly.

Step 1:

Go to: Apple Icon -> About this Mac -> Storage

To see how much space you are using and how much space is remaining on your drive.

Step 2:

If you suspect that something you are unaware of is taking up space on your computer, you can download a 3rd party app that will tell you exactly what is on your drive.  These apps include Grand Perspective and Disk Inventory X, which provide a visual breakdown by cell block of what is on your hard drive.

Step 3:

If you were able to find the files that were taking up the space, you can either delete them or relocate to an external hard drive.

Step 4:

If you were not able to locate the files taking up space from the Mac report in storage, the next thing to do is reindex the drive, which I will show you how to do HERE.