Customize vs Appearance tab in dashboard

Hello,
I am trying to edit the menu icon for my footer menu. My host is dreamhost, using www.remarpro.com as software for my website. The dashboard on the left, only offers the ‘customize’ tab, there is no ‘appearance’ tab to be found. The ‘menu’ editing is offered under ‘customize’ but it does not allow for any extensive edits such as editing the menu icon. I can literally only add a menu title and it’s corresponding link under ‘customize>menu>add menu>customize link’ it creates the menu icon for me which is currently just a link icon. How am I missing this ‘appearance’ tab? How do I get it? Or how can I possibly edit this menu icon another way? I have downloaded a plugin for menu icon editing, but cannot even access any additions through my current ‘customize>menu’ option. Please help!