Please tell me your experience on TOEFL tests

TOEFL in 11 days; a complete beginner
I’m a non-native speaker from India. I’m planning on giving my TOEFL in 11 days, and all the knowledge I have about the test is from reading online articles for the past 2 hours. I have no idea about how the test is conducted (I know the format, but don’t know how it actually feels like giving the test). It would be really great if someone could offer any tips for the prep and also the resources - websites/books they used for their prep. I bought a one month GregMat+ subscription (which I bought for my GRE prep) and have no other clue as to where to prepare from.

Which websites are better for the mock tests - Paid (their Free alternative would be much appreciated too!)

How helpful are the ETS official Books? Is it mandatory to use them, or will preparing from GregMat (or any other course) suffice?

I’ve constantly come across the term “template” throughout the subreddit. Can anyone please help me out with that?

On a certain YouTube video, I’ve come across “Notefull”. How useful is it? Any users, please comment.

I’m planning on giving the test at the centre, any advice for that? (How is giving the exam at the centre like? What all do you have to carry? etc)

Lastly, about myself. I have a fairly good vocabulary and I can speak English Fluently. Any help would be greatly appreciated! Thank you.