PDF files generetion and e-mail problem

[nikolay86]

Hello there,
i am using presta shop from a short time. I just start to adding my products and i noted some things that not working properly.
1. When my customers made an order and they want to print an invoice after that the invoice didn't generate. Presta shop stop loading the page and there is nothing. How can i fix that?
2. My customers don't received an e-mails from my shop. Again when they made an order they don't receive e-mail with their order information or information for payment method. How can i fix that?
3. I noted when a customer complete an order (when click on "I purchase that order' in the final step) Presta shop showing nothing when stop loading. There isn't a massage like 'You place your order successful' or something like that. What should i do?! Is the problems in my server or i have to install something else to work properly persta shop script?

Thanks in advanced!
Best regards!