Can any helpful admin/user advise me how easy it is to transition from an old template to a new one?

I am not a skilled web designer so I tend to find this kind of thing rather daunting.

My current template is 7 years old, and probably looking dated to viewers.

Would anyone be kind enough to take a look at my existing site www.minster-gothic.com and recommend a new template that would be easy enough for a relatively unskilled user to transition to?

Thanks in advance. Dave.