How to windows 10 upgrade to new drive?

Hi! I have a 1 TB HDD that's currently running windows 7 64bit home premium and I'm about to upgrade to windows 10.

I want to put windows 10 on my 120GB SSD, will the windows 10 upgrade that I just downloaded from 'windows updates' in windows 7 allow me to choose my SSD as the drive I want to install windows 10 on?

I have all my data backed up, but I just want to have a clean windows 10 install on my new SSD. What method should I go about doing this?

(PS: I have a windows 7 key, will that be needed? )