A nice start! Similar to pruning a peach tree (back when I had a apricot tree) it's good to remove crossing stems and limbs and generally keep the interior open for good air flow. When it comes to pruning fruit trees it's easier to show than it is to tell. My apricot tree lasted for about 10 years before the local Virginia borers turned it into swiss cheese. It did have a couple of really good harvest years. Happy Harvest!

After reading a bunch about it I decided to cut the starlight middle branch way down to keep the center open, and left the three main branches coming off the trunk. I wish I would have cut it back last year when I planted it, but got it in the ground kind of late.

Here are the after photos, hopefully it will be better for it in the long run.

The after photo definitely looks better ;-)

I'm hoping it will get some new branches near the cut that will grow outward to fill in the rest. And maybe still get a couple nectarines this year.