Running 5 km In Training: Every Day or Every Second Day?

Good afternoon.

1. How to train to run faster? For instance, I run 5 km in 23 minutes but want in 17-18 minutes; I run 3 km in 12.50 but want in 10-11 minutes.
2. How to train for a half marathon and marathon?

Good afternoon.

If a teenager is going to run a biathlon on Saturday, should he train on Friday, the day before, or is it better to rest?

Oleg Sergeevich, good afternoon.

I run half-marathons regularly, my personal record is 1:52:00.

I've finished running season and plan to return to running trainings in spring (in late March or in the beginning of April). I have several questions:

1. What date should I choose for my first marathon's start considering that I plan to return to running trainings in March and let's assume that I'll start to train for a marathon since 1st April? I would like to prepare good, it doesn't mean quickly because my main goal is to run a marathon without injuries.
2. Could you give me some recommendations on training plan: frequency of trainings per week, weekly running volume? How will the weekly running mileage change every month?
3. What's number of speed trainings a week? How many long runs should I do?

Thank you.

Good afternoon.

I'm an amateur runner, not a professional but I'd like to run a half-marathon in spring. Please, tell me how many times a week I should train for?

Good afternoon, Oleg.

My name is Eldar, I'm in Turkey now.

I started running  a month and a half ago and I'm good at it: I run 10 km in 37 minutes.

I've registered for the Istanbul marathon for 10 km.

I run 10 km 2 times a day, in morning and evening. Should I limit the frequency and long of training before the soon start of the marathon?