Query regarding Applying ILR date and documents

Hi,

I am applying for my ILR in the UK. I have few queries which I am mentioning below:

1) Got my visa valid from 25th Sept 2017 but I entered UK on 1st Oct 2017 - continuous period will be counted from 25th sept or the day I entered?

2) While filling the form in the document section for :- "All previous passports, travel documents or national identity cards that you have used to travel to or remain in the UK" I only have single passport so what document to enclose for this section?

Thanks a lot in advance.

Regards,
Pankaj