How to choose VDS capacity for a service?

Question

Network administration

Greetings to all users of the Toaster service! We are developing a website builder service with our team. The task became with the choice of VDS. The service itself consists of:

landing page, pages with a user agreement, a blog, a separate reference site on a subdomain similar to Tilda: help-ru.tilda.ws/, the constructor itself and customer sites that will be created on our service and respectively located on our VDS's.

There are questions about VDS: What power is needed at the start? How many servers do you need? And what are the average prices on the market . Below is an example of a competitor.
1) server 1: main site + admin panel: a competitor has 10,000 users daily visit the site (how many of them the admin panel is not clear)
2) server 2: user sites: 20,000 users visit customer sites daily

Answer 1

Take some small server with 4 cores and 32GB of RAM, with an SSD: so that it is both cheap and holds some load. Then you will select by monitoring.

Answer 2

Anyone with adequate support and scalability.
In general, you need to think about horizontal scaling of the service right away. These are questions for developers and administrators of the service.

Answer 3

Yes, the main thing is to scale. And so the most minimal at first is quite suitable, and then you will increase the power according to your needs.