It is generally the case that there is nothing in Moodle that becomes set in stone. You can always go back and change things later. Resources and Activities in courses can be moved about at will. With editing on, look for the double arrow icon to the right of each resource/activity/block. Once you've clicked the double arrow icon your screen will change and you will see several blank boxes. Click on the blank box where you wish to move your resource/activity/block.