i installed this one bur httpd still won't start.
How to start lamp or httpd?
It is started automatically after addon is installed. But installation takes some time - just wait until you see message in kodi that lamp addon is installed.
Some instructions: OpenELEC Mediacenter - OpenELEC Forum - LAMP addon - Linux, Apache, MySQL PHP bundle (1/30)
If for some reason daemons doesn't start you can see some info with