Question: how much national insurance do i have to pay to get a qualifying year?
Answer: Since 1978 a qualifying year is one in which you have paid (or treated as having paid) contributions on earnings of at least 52 times the Lower Earnings Limit. For the year 2019-20 the lower earnings limit is £118/week so you would need to have been paying NICs on a salary of £6,136 at least.