[Archaea]

You're looking at this incorrectly.

At the speeds you're mentioning, you need to build endurance first. You have no foundation, and worrying about speed will only cause injuries and disappointment.

Read about your endurance foundation before you worry at all about speed.

With that said, how many days per week are you running?

Are you running the same every day? If so, that's your first mistake. You need to vary workouts so that your fitness improves with less work.

A base will take about three to six months. Until you can run five miles easily, you should not worry about speed. Speed fitness comes last of all.

However, the times you're seeking can come entirely through endurance training.

Increase mileage by ten percent per week, for three weeks and then back off during week four.