Hello, I’m fairly new to unity, earlier today I tried creating a project and but I kept getting this error message

I tried fixing it myself by opening the Unity server first but I got another error message saying that only one Unity substance can be opened at once


Do you have a 3rd party firewall installed? Did you check your firewall settings as the error says?
But besides that I’d suggest learning Unity on a stable release rather than an unfinished alpha. Unity 2019.1.8 is the latest version of Unity. Unity 2019.3 you’re using won’t be stable enough for release until around December.