Cables and ropes have been an important knitting design theme for ages, especially in the fisherman knits, since they're so important in seamanship. Without cables and ropes to tie up your boat, you'd soon lose your dinghy!
Try stepping back and taking a look at what you're actually doing when making a cable, which is simply twisting some stitches on one row, every few rows, to make a cable or rope-like pattern.
You've got, for example, six stitches you're working with.
What you're doing is taking the first three stitches and slipping them onto a separate cable needle to keep them secure while you work those second three stitches first.
Then you can either knit those original first three stitches right from the cable needle or slip them back onto your left hand needle and work them from that.
If you hold those first three (on the cable needle) in back of your work while you knit the second three you'll get a cable that twists to the right. If you hold your first three in front of your work, the cable will twist to the left.
You'll only do the twist maneuver every few rows (however many rows the pattern calls for) and then your cable will twist and turn its way up the work making a beautiful pattern in the fabric.
The first cables I did felt so awkward but I just kept at it and it got lots easier with practice.
I hope this helps and please let us know how it's going!