I would definitely advocate for learning in a manual. I got my learners in 2018 and learnt in a manual. While it is harder, I think the additional skills learnt are very valuable.
Not only is it a useful skill that comes in handy occasionally; (its shocking how many people cannot drive manual) whether its moving a work car, or sober driving a mate's car, I think learning in a manual gives you a better understanding of driving dynamics such as; braking and shifting before a corner, anticipating whats ahead of you etc.
My experience with insurance is that for "regular" cars AMI Young Drivers' Insurance is generally the cheapest.
I somehow managed to get my 540i insured by them back in 2020 for a reasonable amount (although I think they have changed their insurance matrix since then as they would not cover my W8s, Boxster, Legacy, S8, S6 etc). I also had a cheap Mazda 6 and Mercedes A170 which they insured for a minimal amount.
Otherwise, AA insurance usually ensure the more powerful/niche cars but that does come at a bit of a premium.