Can I change a blogger template without losing my content? In other words will I lose my content if I change my template?
Changing template won't effect your post, but it might effect your widget (some widget might be deleted when a new template is installed).
Yes... You can very well change the template without loosing the content... The widgets (some) will be lost. You can have a backup of most of the widgets if they are in the HTML/javaScript form.... and then use it in the new template.