grape vine

That is not a great photo graph but to be honest there are established ways to prune vines. You can use the Guyot method or you can do cordon pruning. I have done both and they are very simple and both work well. You can find lots of stuff on pruning and establishing grape vines on the internet and to be fair it is much easier doing this than trying to explain the methods on a forum.  One thing that is really good about grape vines is they are very forgiving to the clumsy pruner  they do re- grow well AND you can change your desired method of pruning from one method to another. I hope this helps you because I am not going to try to explain the ways of pruning it would take far too long. One thing you do have to understand though is that getting decent grapes in the UK is not easy you need to protect the vines and have them in a sunny spot against a south facing wall is favorite.