How do I edit the html of my wordpress site's main menu bar? (would like to add a site logo to it) – CPanel

I’m using the Underscores theme for my wordpress site so everything is very plain and there’s no option to add a logo to the menu bar (at least not that I know of ).

Is there a way to edit the html of the menu bar by accessing a certain file on my site from the backend (cpanel or something)? I’ve read online it might require putting php code in my functions.php which doesn’t make sense to me because I thought the menu bar is created with basic html/css.

Here’s my current menu bar’s setup. I’d like to simply add another div before menu-main-container div so I can add a logo to it.

<nav id="site-navigation" class="main-navigation">
            <button class="menu-toggle" aria-controls="primary-menu" aria-expanded="false">Primary Menu</button>
            <div class="menu-main-container"><ul id="primary-menu" class="menu nav-menu" aria-expanded="false"><li id="menu-item-219" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-home current-menu-item page_item page-item-88 current_page_item menu-item-219"><a href="http://shegames.net/">Home</a></li>
<li id="menu-item-1312" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-1312"><a href="http://shegames.net/my-account">My Account</a></li>
<li id="menu-item-1313" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-1313"><a href="http://shegames.net/checkout">Checkout</a></li>
<li id="menu-item-1314" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-1314"><a href="http://shegames.net/cart">Cart</a></li>
<li id="menu-item-1315" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-1315"><a href="http://shegames.net/shop">Shop</a></li>
</ul></div>     </nav>

Assistance would be very much appreciated. I’m really interested in learning how I can just edit the html myself for the menu bar so I can make more complex customization in the future…preferrably without relying on php or other code besides html/css…idk if that’s possible though.