Advice on customising a photography portfolio theme

Hi ! I’m a photographer and this is my first post so excuse any lack of knowledge 🙂

I’ve just installed WordPress and a custom (plug in) theme for my portfolio website http://www.rodedwardsphoto.co.uk.

I’ve got the three main image galleries working (Places, People, Tourism) but need to customise the theme to support links to external pages.

1 ) My “Interactive” gallery has thumbnail images that when clicked on need to link to a .html file. How do i do this ?

2 ) My “Video” gallery has thumbnail images that when clicked on need to link to my Vimeo video files. How do i do this ?

3 ) My “Information” page needs to also be slightly customised – I need delete the ‘Header Text’ (Information). How do i do this ?

Any advice would be amazingly helpful as i’d like to make my portfolio site work well and look pretty ! Thanks in advance … Rod