
I can see a few major cut to get a more triangular shape to it but a few more pictures would help to give a more informed suggestion. You could take it to a club to get an opinion in person, which is a great place to get advice and learn.
Keeping it alive is always the first priority. Look after it for a few weeks before working the tree just in case the tree has been stressed before you got it home. Using the time you could check out the wiki and search some topic to find a tree design you want.
A good time to do work on a juniper is when they start producing new growth at the tips, as a general rule. Its when you tip prune the new growth to keep the foliage compact.
Patience is often a surprise.