Can't change widget titles

If you’re using the pre-installed settings that come with the theme (you check one or more boxes for recent comments, tags etc) then these are fixed. They’re meant for people who just want something simple straight out of the box. If you want to start changing widgets around then you need to go to Appearance / Widgets and drag widgets into the areas on the right e.g. sidebars, footer etc. Once you’ve dragged a widget there you can add your own titles etc.

WordPress comes with a selection of widgets in Appearance / Widgets but if you want other ones either click ‘Plugins’ in the left of the Admin pages, click ‘Add New’ at the top and search for something like ‘Recent comments widget’ OR search the internet for a widget, download to your computer and upload by going to Plugins / Add New / Upload (small writing near the top of the page)