WiFi - Activation of network connection failed

Hello everybody,
today I have started my very new experience with Linux. I have installed Zorin OS on my pretty old notebook HP 620 (via ethernet) and voila - the first problem is here. When I try to connect via wifi, there is a error message “Activation of network connection failed” and I don’t know why.
Please, could anyone help me to find and install drivers for Realtek Radio Model RTL8191SE? Thank you.

Hi, aish.cz.
For your message, can you try this?
https://appuals.com/activation-of-network-connection-failed-in-linux/
If those suggestions don’t work, try sudo apt-get install --reinstall network-manager in terminal (ctrl+alt+t). But first try the appuals suggestions.