Need to delete few things, can you help me?

Hi!

I need to delete few things in front-end...

- Post comment as a guest ==> where can i delete the sentence or modify it at least ?

- Permalink ==> Can i delete it or someone can tell me what is the purpose of it?

- like button (heart) doesn't work ==> do i have to install something else? When i click on it, nothing happens but i can see : javascript:void(0);

Thank you very much for your precious help!

Have a nice day