Port 8000 vs Port 8080

It doesn't matter. In fact, 8080 is often used as a default http port for software providing http services that is not a core http Server (e.g. Apache http Server). So after a while this port is sometimes taken from software that runs on the system in a background. 8000 it seems is just another port being used by the .NET domain. Ports below 1024 need system user permission like root or something. That is why ports in the thousands are used for software running as a normal user.

No difference. Two common ports you'll want to know the difference between 80 and 443. 80 is for insecure (HTTP) connections and the other one is for secure (HTTPS) connections, but they both are used and reserved for HTTP communication.