Hi Autumn. I'm Greg, an installation specialist and 8 year Windows MVP, here to help you.
To answer your question, yes you need to type Default into Start Search, open Default Apps, scroll down to Choose by File type, then to the .pp** files types to see that all of them (except html which is web based) are set to Powerpoint. If not click on the app to change it.
I hope this helps. Feel free to ask back any questions and let us know how it goes. I will keep working with you until it's resolved.