Here's a step-by-step guide on how to install a WordPress theme:
Step 1: Log in to your WordPress dashboard. To do this, enter your website URL and add /wp-admin to the end of it (e.g. http://example.com/wp-admin). Then enter your username and password to log in.
Step 2: Once you're logged in, click on the "Appearance" tab on the left-hand side of the dashboard.
Step 3: Click on the "Themes" option.
Step 4: Click on the "Add New" button at the top of the screen.
Step 5: You can search for a theme using the search bar or browse through the Featured, Popular, or Latest themes. Alternatively, if you have a theme file downloaded to your computer, you can click the "Upload Theme" button to upload the theme file.
Step 6: Once you have found the theme you want to install, hover over it and click on the "Install" button.
Step 7: After the installation is complete, click on the "Activate" button to activate the theme.
Step 8: You can customize the theme by going to the "Customize" tab in the Appearance section.
Congratulations! You have successfully installed and activated a WordPress theme.