You can care for this in container indoors pretty easily. Just make sure it is in a brightly lit area, and receives a 2 or 3 day dry period before watering again. Only water after it has dried to prevent root rot. Other than that there is not much care required to keep it alive until you can plant the tree.
Here is an article for more care on established trees: https://www.gardeningknowhow.com/ornamental/trees/colorado-blue-spruce/care-for-colorado-spruce.htm