Help! Template changed all sudden and won’t let login

im not sure what happend but I spent the day trying to fix it. I used the default template and everyting has been working for at least 2 months. Today the template has changed (doesn’t have any format) and when i click login doesn’t come up with login screen. Site is https://www.itraveltofrance.com If any one has any idea please help. Also more than happy to pay a geek for assistance. Have money no brain cells