I dont know what to do

I tried plex on my laptop to check it out a long time ago. then i liked the idea of it and installed on my PC. i could not access anything from my PC. soi deleted plex and forgot about it, have used EMBY for a very long time now. recently tried to install plex on my PC and it wont let me open a server because it is all linked to my laptop

I’m not really clear I understand the problem at hand.
You have installed the current version of Plex Media Server on your PC?
Can you access it locally on that PC by opening http://127.0.0.1:32400/web in a browser on that PC?
Have you linked the Plex Media Server on that PC to your Plex account?
Is the installation of your original Plex Media Server on that notebook still active?

From the sound of it you’re opening Plex through an app or the online version of the Plex web interface (e.g. http://app.plex.tv/desktop) – this will only work after you you completed the setup of your server.
See e.g. the last step in the related support article.

If you cannot get to the settings of that new server by opening it locally (http://127.0.0.1:32400/web), you might have linked it to a different Plex account in the past. There’s another support article addressing this – but let’s go one step at a time…

Perform a “thorough” uninstallation of the old Plex server installation: Uninstall Plex Media Server | Plex Support