theme not showing in customize

hi, i am new to wordpress. i have installed oceanwp theme and twenty twenty-one theme. before installing i checked a preview. full theme, i mean webpage images menu logo, everything is showing. now i installed and activated a theme oceanwp.. after activation i clicked on customize.. in customize page on the right hand side only blackground and some text is showing… right now i have still not created any post or pages…. but atleast when i click on customize it should show full web page what i saw in preview before activating the theme.

• This topic was modified 9 months, 3 weeks ago by sfn786.