Change php to list images in a row

Hello,

I am rather new to WordPress. I need to change my boss’ Portfolio page to list all of the images in rows of four, rather than a single column.

The Portfolio Page Template php is calling all of the posts with the portfolio category and displaying the associated Featured Image.

Here is the code in question:

<ul>
			<?php if (have_posts()) : while (have_posts()) : the_post(); ?>
					<li class="portfolioItem">
                    	<a href="<?php the_permalink() ?>"><?php the_post_thumbnail(); ?></a>

					</li>
			<?php endwhile; ?>

   	 </ul>

This is the page I’m working on: https://vmvbrands.com/category/portfolio/

Let me know if more information is needed.

Thank you,

Judah