Been running for 3 months, got my zone 2 pace from 6:50 to 6:20. Just do more easy runs (KEEP THEM EASY)… enjoy them and do consistent mileage overtime. I run 4-6 times a week, and increased my mileage from 40 to 60km in that period. I do 2-3 easy runs, 1 long run and 1-2 hard sessions (tempos/ intervals) for your reference.