You subscribe on the site and it lasts 30 days from payment. It doesn't renew by itself, and nothing is charged without your consent.
You subscribe on the site; there is nothing to buy in the launcher.
Payments go through the Robokassa payment service. Which methods you can use (bank card, the Faster Payments System and others) Robokassa shows on its own page at the moment of payment. The receipt comes from it as well.
30 calendar days from the payment date, not until the end of the calendar month. How many days are left is shown on the JustFollow page.
No. The subscription does not renew automatically, and no money is charged without your separate instruction. When the 30 days end, the extra features turn off. To get them back, pay for the subscription again.
Only someone who may enter into such transactions on their own can pay for the subscription. If you are younger, ask a parent or another legal guardian to pay.
The full terms are in the offer.