Need help with #masthead .hgroup h1

Hi guys,

Hope you are fine and well! :)

Coud you please help with the following:

I want to have only 1 H1 tag on all my pages and I’ve just found that there us the following code:

<style type="text/css" id="customizer-css">#masthead .hgroup h1, #masthead.masthead-logo-in-menu .logo > h1 { font-size: px } .entry-content { font-size: 14px } .entry-content, #comments .commentlist article .comment-meta a { color: #000000 } .entry-content a, .entry-content a:visited, #secondary a, #secondary a:visited, #masthead .hgroup a, #masthead .hgroup a:visited, .comment-form .logged-in-as a, .comment-form .logged-in-as a:visited { color: #f90000 } .main-navigation ul { text-align: center } .main-navigation { background-color: #0076b2 } .main-navigation a { color: #ffffff } .main-navigation ul li:hover > a, #search-icon #search-icon-icon:hover { background-color: #0da300 } .main-navigation ul li.current-menu-item > a, .main-navigation ul li.current_page_item > a  { background-color: #0da300 } .main-navigation ul li { font-size: 14px } a.button, button, html input[type="button"], input[type="reset"], input[type="submit"], .post-navigation a, #image-navigation a, article.post .more-link, article.page .more-link, .paging-navigation a, .woocommerce #page-wrapper .button, .woocommerce a.button, .woocommerce .checkout-button, .woocommerce input.button, #infinite-handle span button { text-shadow: none } a.button, button, html input[type="button"], input[type="reset"], input[type="submit"], .post-navigation a, #image-navigation a, article.post .more-link, article.page .more-link, .paging-navigation a, .woocommerce #page-wrapper .button, .woocommerce a.button, .woocommerce .checkout-button, .woocommerce input.button, .woocommerce #respond input#submit.alt, .woocommerce a.button.alt, .woocommerce button.button.alt, .woocommerce input.button.alt, #infinite-handle span { -webkit-box-shadow: none; -moz-box-shadow: none; box-shadow: none } #main { background-color: #ffffff; background-image: url("http://basni-krylova.ru/site-content/uploads/2016/01/fonovaya-kartinka.jpg"); background-size: cover } #colophon, body.layout-full { background-color: #e5e5e5 } #colophon { background-image: url("http://basni-krylova.ru/site-content/uploads/2016/01/fonovaya-kartinka.jpg") } #footer-widgets .widget { color: #000000 } #colophon .widget_nav_menu .menu-item a { border-color: #000000 } #colophon #theme-attribution, #colophon #site-info { color: #000000 } </style>

How is it possible change or remove it? And why there are a lot of .woocommerce when I don’t have woocommerce plugin at all?

Thank you in advance!

Best regards,
Andy