Setting up a Proxy Gateway with 1 server that forwards requests to other servers?

Hello. So I'm not sure if what I'm about to describe is a "Virtual private network", but essentially what I would like to achieve is the following:

Let's say I need to set up Microservices. We need 1 gateway that is public and is accessible to any other host that wants to make a request or connection to it, this would be the "proxy" takes in requests. This proxy would or could have an authentication server set up so it'll check if the user is authenticated, or have them authenticate so that a session is created.

Every time they use our client (our frontend app or if they want to make a request to our API), we would check the credentials at the proxy level, and if it's valid we'd forward the request straight to our "microservices", which would be apps that sit behind a firewall or in the private network that is only accessible from the gateway server.

If this is so, is it a recommended way to set up your own microservice architecture? Is it a good idea to have 2 servers, one with a firewall that only allows HTTP(s) to the IP of the gateway, so that no one else can target it directly?