Glad you got the net light to blink. I assume it would be the fast blink (4G network).
Does the net light change to ON when you try to connect to your phone, as per the table above ??
If the message no carrier appears straight away then the board may not be configured correctly.
Have you followed the Waveshare instructions for the software setup on the PC ??
Have you installed the debugging assistant ?? (it may or may not help)
Do other AT commands work ok ??
The net light blinking indicates the board is functioning to a certain level and detects a network. The blink rate indicates which type of network it is detecting. I don’t think 2G networks exist anymore and there is talk of 3G being phased out (but I might be wrong there)
The no carrier message indicates the board is not detecting what it needs to establish a dialing connection to call your phone.
The Phone Call section of the web page shows some commands you can use. If you know the SIM card phone number you could try calling the board with your phone and if the board detects it.
The FAQ section has no carrier area, it may give you a clue as to why it is not working.