Your third year from planting will give the vines a chance to establish themselves and form a strong support vine that can handle the weight of fruit. Search on the site and you will find a pretty complete growing guide.

Grape:

I planted some grapevines from Schlabach's in New York.
Concord and Canadice. I found them to be nice sized
bare-root plants and relatively inexpensive.

I had a few of the concords bear the first year. I should have removed all the fruit, but I did leave one bunch on.

The second year I had a great crop as they grew to 5' already the first year. The 3rd year was even better as now full grown on my 4 arm kniffen system.

Not sure about the quality of grapevines from stark's but
I will be ordering a few more vines from Schlabach's for next spring. I am too busy to propagate my own but my
brother does from hardwood cuttings for his horticulture
class he teaches. It is not difficult to do and after rooting out and growing for one year they are ready for the vineyard.

Just an FYI that David Schlabach does offer a lot of seedless grape varieties.