How do i set up a blank artboard?

Hi,

I'm a beginner with Illustrator. I am using Illustrator CC 2017. When i click 'new' the program only gives me templates such as 'bold postcards' or 'app designs' to start with.

I simply want to be able to make a bespoke and specific artboard size with a white background so that i can start drawings and designing. I don't want to start with a preset because i don't know how my design will turn out. I used to be able to do this before with previous versions of Illustrator but now i cant.

For example i am designing some birthday cards and they are only 20cm high but 60cm wide. There is no preset for such a specific thing.

Any ideas how i can make my own blank artboards? Is there something i am missing? or is everyone starting with the 'bold postcards' and then having to delete the preset stuff?

Any help would be appreciated.

Thanks,

H