Answer: The weeping form of blue atlas cedar (Cedrus atlantica 'Glauca Pendula') droops dramatically. If this is what you have, there is nothing you can do to make it grow upright. Blue atlas cedar (Cedrus atlantica 'Glauca') tends to have a somewhat irregular look rather than the stiff uniform Christmas tree shape, although it does grow up overall. The branches may seem a bit wavy but over time it would naturally grow upright.
Without seeing the tree it is very hard to give specific pruning advice. Usually, it is not a good idea to remove the leader branch at the top of a tree. I would suggest you take some photos of the tree and consult with your local professionally trained nurseryman and/or your county extension to see if it would be advisable to remove one or both of these top branches or shorten one of them to redirect the new growth.
I would suggest you try to see this tree grown to maturity and check if it is going to develop into the type of tree you have in mind. For a more traditional stiff pyramidal evergreen look, you might want to consider a different plant. Colorado blue spruce for instance has that look, however it would not grow well in your hot summers. Your local nursery staff and/or county extension should be able to recommend trees that would thrive in the growing location where you want to plant and also meet your design goals.
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