How to Show all Values in category.php page using post_type

You’re calling wp_reset_postdata() and closing the loop before displaying the content of the posts.

The WordPress Codex has a good example of how to build a custom query:

<?php
// example args
$args = array( 'posts_per_page' => 3 );

// the query
$the_query = new WP_Query( $args );
?>

<?php if ( $the_query->have_posts() ) : ?>

    <!-- start of the loop -->
    <?php while ( $the_query->have_posts() ) : $the_query->the_post(); ?>
        <?php the_title(); ?>
        <?php the_excerpt(); ?>
    <?php endwhile; ?><!-- end of the loop -->

    <!-- put pagination functions here -->
    <?php wp_reset_postdata(); ?>

<?php else:  ?>

<p><?php _e( 'Sorry, no posts matched your criteria.' ); ?></p>

<?php endif; ?>

I’ve fixed the code for you here and added some comments:

<?php get_header(); ?>
<div id="section1-inner">
    <div class="container">
        <div class="row">
            <div class="col-lg-3 col-md-3 col-sm-12 col-xs-12">
                <div class="left-sec1">
                    <img src="https://wordpress.stackexchange.com/questions/248557/<?php bloginfo("template_directory'); ?>/images/logo.jpg"  alt="">
                </div>
                <div class="left-sec2"><h2>Category</h2></div>
                <div class="left-sec3">
                    <ul><?php if ( !dynamic_sidebar('Product Category') ) ?></ul>
                </div>
                <div class="left-sec4">
                    <ul><?php if ( !dynamic_sidebar('Homepage Banner') ) ?></ul>
                </div>
            </div>
            <div class="col-lg-9 col-md-9 col-sm-12 col-xs-12">
                <div class="form-gap"><?php get_search_form(); ?></div>
                <div class="gallery"><?php wd_slider(1); ?></div>
                <div class="clearfix"></div>
                <h3 class="title"><?php printf( __( '%s', '' ), '<span>' . single_cat_title( '', false ) . '</span>' ); ?></h3>
                <?php
                $query = new WP_Query( array( 'post_type' => 'product', 'orderby' => 'menu_order', 'order' => 'ASC', 'showposts' => 5) );
                if ($query->have_posts()) : // Always check if there are any results before looping
                    while ( $query->have_posts() ) {
                        $query->the_post(); ?>
                        <div class="col-lg-4 col-md-4 col-sm-6 col-xs-12">
                            <div class="pbox">
                                <center><?php the_post_thumbnail(); ?></center>
                                <h3><a href="<?php the_permalink(); ?>"><?php the_title( ); ?></a><br></h3>
                                <h4><?php the_field('offer_price', $taxonomy); ?></h4>
                                <h5><?php the_field('price', $taxonomy); ?></h5>
                                <p class="text-center"><a href="<?php the_permalink(); ?>"><img src="https://wordpress.stackexchange.com/questions/248557/<?php bloginfo("template_directory'); ?>/images/download.png" alt=""></a></p>
                            </div>
                        </div>
                    <?php }
                    wp_reset_postdata(); // Called after the while loop for the query finishes
                endif; ?>
            </div>
        </div>
    </div>
</div>
<?php get_footer(); ?>

Edit: After reading your comments, it seems like what you want to achieve is showing only the posts for the current category. You’ve taken a different approach to this by setting up your own WP Query, so you’ll need to add another argument to get the posts for the currently queried category, using $wp_query->get_queried_object_id().

Replace your $query = ...-line with the following:

$query = new WP_Query( array( 'post_type' => 'product', 'orderby' => 'menu_order', 'order' => 'ASC', 'showposts' => 5, 'cat' => $wp_query->get_queried_object_id()) );