kdplanning,
Yes, a screen shot would be very helpful, but meanwhile, a few comments.
First, you mentioned that you entered key dates. Hopefully you did not manually enter start and/or finish dates to any tasks or milestones. Doing so creates a constraint and basically defeats the dynamic scheduling of Project. If you need to "drive
stakes in the ground" for key activities/milestones, use the Deadline field.
Second, make sure your installation of Project is updated with the latest Public Update. For Project 2013, that is the January 2016 update. You can update simply by running Windows update.
Third, assuming your installation is fully updated, the strange behavior suggests your file may be corrupt. See the following Wiki article:
http://social.technet.microsoft.com/wiki/contents/articles/32054.ms-project-clearing-file-corruption-andor-bloat.aspx
John