If I pay for the plan 19/month, I will get 10 sites available. Will I get them for life or must I pay the subscription every month?
Please answer
Hey @Mohamed_Reda and welcome to the community! 
There are two types of Webflow plans — Workspace plans and Site plans.
Workspace plans (the type you mention in your post) aren’t required to use the platform or publish websites, but remove specific limitations, like the amount of staging sites (published websites that utilize the .webflow.io domain) you can have. Realistically, unless you’re regularly building multiple sites simultaneously and need to have more than 2 staging sites at once (this is the Free plan limitation) — or you want to export your project to host externally — then you don’t need a Workspace plan.
Site plans on the other hand are required for every website you want to publish to a custom domain — regardless of a free or paid Workspace plan. These either renew monthly or yearly, and can vary in price depending on the features you’re looking for: