WordPress Custom theme help – Navigation bar

Hi,

my name is Fallak and I’m new to word press. I needed a template for a website downloaded it but now I’m stuck. The navigation bar appears as a column going downwards on my website wwww.igloolettings.com/wordpress. Basically I need to some how change that navigation bar so it goes in a row like:

Home Lettings Contact

I have tried changing the header menu but there is only one and I’m guessing its the default theme for the template.

Would be really nice if someone could help me out thanks with codes and what ever is needed to create a row navigation.