I have no experience with grape vines .... but when I trim the very thick vines from my neighbor's algerian ivy, which is destroying my fence, I twine it around the base of a 5gal bucket, until it is dried. Then twine smaller twigs in and out through the dried vines .... makes a half-way decent looking garden 'wreath'.

ooops! Forgot to mention that grapes grow wild here. They can be a nuisance when they come up on fence lines or power lines etc. I watch them every year and try to get them when their ripe but it's futile. One day they aren't quite ready and the next the birds have already been at them. I swear that they just roost in the vines at night and then when they wake up in the morning they sniff the fruit for ripeness and then dig in! Little stinkers lol! At Thanksgiving time when my kids come for the holiday we go out and collect the vines. Then we spend an evening making them into wreaths and things and decorate them for Christmas. They love giving them to co-workers and friends as holiday gifts. MeMo

Peter - you could ask on the Fruit and Orchards Forum which is where the fruit growing experts hang out. Despite its name this forum tends to be mostly about ornamentals and wild plants.

No. You only have the young main cane so far so do no pruning this year. You might plan your support which is usually 2 or 3 lateral wires onto which you can train vines, 2-3 to one side and 2-3 to the opposite side. Next year you should be able to select those laterals and prune all others to 2 buds per vine coming from those laterals. The height of the lateral lines may vary but you might try 30", 50" and 70" from the ground.