Great first try. The wiring appears neat and looks like it is effective which is better than many first tries.
As far as style I find myself questioning why one half grows up and the other half down. A good bonsai should tell the viewer a story of it's life or place in nature. My mind is asking where did this tree grow in nature? What is it's story? If it grows on a high mountain with regular snow, avalanche and katabatic wind it's likely the growth will mostly be downward. In a slightly less hostile area growth is more likely to be upward as most trees are strongly apical dominant but it would be very rare to see both cascade and upright growth on a single tree.
From a horticultural point of view I think you are likely to have some problems with both upright and cascade on one tree. Apical dominance will make the upper part grow stronger and quicker while the cascade section is almost certain to get weaker unless you selectively trim very carefully.
You may have had to take off most of the inner branches - too long, too weak, etc - but it seems to pay to keep some of them as junipers don't always back bud along bare branches which may mean those open areas won't fill in for a very long time, if ever.
The main trunk has some great bends but the smaller branches are still very straight, even those with wire on. I would consider putting some bends into those branches to match the shapes in the trunk.
For now the tree has probably had enough of a scare. Best to let it alone for a few weeks at least to get over the initial trauma before doing more work.