Looking to buy a BMW as my first car, but which one?

I am 20, budget of £10k, had my license for 3 years.

For reference, insurance on 330e 2L is £2400, and insurance on a 318d 1.5L is £1100.

I just do not know what model to go for, what max mileage to look at and what year min to look from.

I heard n55 engines are unreliable so I want to avoid those, other than that, what is something with the least likelihood of causing lots of issues which increase costs?