Get password protection form at the front page

Hey! I am using a theme that does not have the inset password form at the front page, and i need to click into the specific post to enter the password. I want to change this so i get this “enter password” form at each post without clicking into it.

I have been reading around, and found a few codes, but since I am lacking php experience i am having problems fixing this issue. I am not even sure what i need to change or where, and when i try to change the functions.php my whole page becomes blank, so i must be doing something really wrong.

So, am i gonna change the functions.php OR the content.php to fix this? And where exactly am i gonna put it? As i said, when i change things my page goes bank, so i need a really simple and specific guide ??

Here comes my content.php:

And here is my functions.php: