Displaying page content - wordpress

Question

I have two codes. The first one I am using on page.php and it displays content from any pages I create in the admin panel. The second code works to display my posts on the mainpage just not sure where that code should go.
It works if I place it in the page.php but then the same content (posts) are shown on any pages I create. I tried placing the second code in home.php and index.php at the same time as using the first code in page.php but does not work.
if (have_posts()): while (have_posts()): the_post();
wp_title(''); echo '<br />';
the_content(); echo '<br />';
endwhile; endif;
<--- Second Code -->
$args = array( 'posts_per_page' => 10 );
$lastposts = get_posts( $args );
foreach ( $lastposts as $post ) :
setup_postdata( $post ); ?>
<div id="pbox">
<div id="pthumb"><?php the_post_thumbnail( array(100,100) ); ?></div>
<div id="pcontent">
<?php the_title(); ?>
<?php the_excerpt(); ?><br />
Post Category: <?php the_category( ', ' ); ?>
</div>
</div>
<?php endforeach;
wp_reset_postdata(); ?>

Answer 1

I think you should take a look at the following: https://developer.wordpress.org/themes/basics/template-hierarchy/#home-page-display
You'll notice that, if present, home.php is the file that WP will use to display your posts page - if of course a page separate to your normal front page has been set in Settings > Reading > Posts page.
Then in home.php, you can add whatever you like, ie -
<?php
$args = array(
'show_option_all' => '',
'orderby' => 'name'
);
wp_list_categories( $args );
?>
To clarify, if home.php doesn't exist in your theme, WP will then look for index.php.

Answer 2

There are same query post for page.php,single.php because it will just fetch content. you can differentiate by as follows.
Home Page display add same code (query post) in fallowing
1) home.php
2)index.php
front-page.php – Used for both “your latest posts” or “a static page”
as set in the front page displays section of Settings → Reading.
home.php – If WordPress cannot find front-page.php and “your latest
posts” is set in the front page displays section, it will look for
home.php. Additionally, WordPress will look for this file when the
posts page is set in the front page displays section.
page.php – When “front page” is set in the front page displays
section. index.php – When “your latest posts” is set in the front
page displays section but home.php does not exist or when front page
is set but page.php does not exist.
Single Post
The single post template file is used to render a single post. WordPress uses the following path:
single-{post-type}-{slug}.php – (Since 4.4) First, WordPress looks
for a template for the specific post. For example, if post type is
product and the post slug is dmc-12, WordPress would look for
single-product-dmc-12.php.
single-{post-type}.php – If the post type is product, WordPress would
look for single-product.php.
single.php – WordPress then falls back to single.php.
singular.php – Then it falls back to singular.php.
index.php – Finally, as mentioned above, WordPress ultimately falls
back to index.php.
Single Page
The template file used to render a static page (page post-type). Note that unlike other post-types, page is special to WordPress and uses the following patch:
custom template file – The page template assigned to the page. See
get_page_templates().
page-{slug}.php – If the page slug is recent-news, WordPress will
look to use page-recent-news.php.
page-{id}.php – If the page ID is 6, WordPress will look to use
page-6.php. page.php
singular.php
index.php
Detailed Explanation: click here