VPN says “connecting” for long period and I can’t connect to my WiFi

If you cannot connect to WiFi, temporarily disable your VPN App/connection. This will likely resolve the issue, allowing your iPad to connect to the WiFi network - after which you can re-enable the VPN.

Are you using a VPN App - or have you simply manually configured a VPN connection in Settings?

If you are using a third-party VPN App, there is strong possibility that you have configured Connect On Demand somewhere in the individual App settings. This configuration setting may be worded as something else by the App (e.g., Kill Switch, Persistent Connection etc.) but it will have the same effect. Either way, this setting can interfere with the DHCP handshake that assigns an IP Address to your iPad.