Post doesnt apear to be working.

I am making a custom theme, im trying to call my posts and show them.
So i run this loop :

<?php if (have_posts()) : ?>
<?php while (have_posts()) : the_post(); ?>
<?php the_title(); ?>
<?php the_content(); ?>
<hr>
<?php endwhile; ?>
<?php endif; ?>

All that this does, is show my main_nav_menu, it doesnt show any post content at all, ive tried looking up why this happends, all ive found is that the_title is also used for menu’s, so i tried this also:

<?php  if( is_admin() || !in_the_loop() ) {?>
<?php if (have_posts()) : ?>
<?php while (have_posts()) : the_post(); ?>
<?php the_title(); ?>
<?php the_content(); ?>
<hr>
<?php endwhile; ?>
<?php endif; ?>
<?php } ?>

But this does exactly the same.