Has anyone getting an education visa recently?

I'm wondering if when I apply for the visa and it asks for the duration of the course if I put 4 years as I will be attending a 4 year program at a University. Or just 90 days as that's that initial stamp.

For the covid insurance coverage it says it needs to cover the duration of my stay. Will I need proof of coverage for 4 years or just 90 days?

Any info you can provide would be greatly appreciated. Thank you all!