There are 4 main steps for WiFi to work and you’ve passed the first hurdle.
- The radios establish a two way link on the SSID - agreeing on channel, encryption, and what if any password your client needs to be let on.
- The computer optionally asks for an address to be assigned (DHCP request) over the working radio connection.
- The receiving access point will either answer that request or broadcast / assign it to another device to handle.
- The response is delivered to your Mac which needs to configure itself for the DNS/DHCP address and subnet assigned.
The last three steps could be combined into one if you know all the settings and set up your network automatically. Since you have the message “does not have an address” one of the three things that happen externally has failed so you’ll need to manually configure the network settings or ask for help.
Since the radio is up, you could run a packet capture tool like
sudo tcpdump -i en0 with en0 possibly being another number on your system and look for those DHCP broadcast or ARP requests and figure out what network address might be available - but that borders on setting up the network so it’s really best to not potentially break the network for everyone if you assign yourself an address that was reserved or is in use already.