1st attempt cableing

This is my first time attempting cable
Are the gaps/holes supposed to be there or is my tension off?

Thanks!

That is normal on the left side.

You can minimize it by wrapping the first purl under instead of over. If your project is flat you can then untwist the stitch on the back side. This method works because it shortens the strand used for the purl stitch.

OR

Just ignore those gaps and consider them just part of cabling. They can sometimes even out a bit in the wash.