As an update I’ve managed to access the box now (It put out a OpenWRT SSID which I didn’t know about and it allowed me to connect via Wi-Fi) and it seems to be running ok. I still need to get my head around all the settings interfaces and networks etc.
The IP range the OpenWRT box gives (192.168.1.1/255) is the same an my home network, in order for these to play together should I setup the box on a different range (192.168.2.1/255 for example).
Thanks for all the help on this