The thing to keep in mind is that your main aim is always to get the grapes as ripe as possible. This isn't as easy as it may seem, grapevines are subject to many pests and diseases, it is different in each area. It is important to keep your foliage as healthy as possible, so get to know the sprays for things like powdery and downy mildew, downy is the biggest problem. Always keep the weeds down through the growing season. It is easier to ripen a small crop than a big one, you should plant your vines much closer than that, though with only 17 vines it's understandable you wanted to cover some area. About 3 feet apart is a good distance, possibly a bit wider. I asked the viticulturist at the vineyard where I used to work what he would change about the vineyard if he could, he said he would plant the vines closer (they were about 8 ft apart). It is easier to grow good grapes if the vines are smaller, though it is possible at wider spacings.
When the vines are mature and vigorous you have to keep the crop level down, don't leave too many buds at pruning and don't overwater through summer. With reds the skin to juice ratio is very important, if you can keep the berries small you get much better wine, and they ripen much easier. be sure to get a refractometer and test the sugar often through the ripening period. You need a sample of at least 20 berries from different bunches at random to get a good sample.
That is just a few of the things I have learnt over the years. You will make lots of mistakes but as long as you learn from them you will always improve. Never just blame problems on bad luck, there is always something you could have done better to make things work. Basically any problems are your fault, just accept that and move on.
Also think about bird netting, with a small vineyard it doesn't take many birds to finish your crop.
You are lucky to be able to buy small quantities of vines, in Australia anything less than a thousand vines and the suppliers aren't interested.