How to install themes?

You need to go to Nightlife's page right here, download the theme, unzip it, and then upload it via ftp to your Wordpress install's theme folder. Follow this link, it should help:

http://codex.wordpress.org/Using_Themes

From the Codex specifically:

To add a new theme to your WordPress installation, follow these basic steps:
1. Download the theme archive and extract the files it contains. You may need to preserve the directory structure in the archive when extracting these files. Follow the guidelines provided by your theme author.
2. Using an FTP client to access your host web server, create a directory to contain your theme in the wp-content/themes directory provided by WordPress. For example, a theme named Test should be in wp-content/themes/test. Your theme may provide this directory as part of the archive.
3. Upload the theme files to the new directory on your host server.
4. Follow the instructions below for selecting the new theme.

To select the active theme for your site:
1. Log in to the WordPress Administration Panels.
2. Select the Presentation subpanel.
3. From the Select column in the table, click on Select for the theme you wish to activate.
4. To view the new look, click View Site at the top of the Panel's screen.

Your selection should immediately become active.

I have installed the nightlife theme on my blog.
But... there's an issue in it:
1. the left bar search show me ":" then the search bar and under the bar the button "search". I saw the nightlife theme here and doesnt show the button because is hidden. Also doesnt show me the admin widget. I do not know what im doing wrong or if it something about the programming code of the style.

Anyone could help me with this!?

PEACE