I am trying to install Ubuntu 20.10 on my raspberry Pi 4 8Gb RAM using a 16 Gb SD card. I have followed this tutorial exactly. I have tried to install it using wlan0 or eth0 by modifying the network-config file as:
#ethernets:
eth0:
dhcp4: true
optional: true
#wifis:
wlan0:
dhcp4: true
optional: true
access-points:
"My network":
password: "My password"
but I am always getting stucked at the cloud-init point. I am getting exactly this:

It hangs on until I press enter. Then I get to the login prompt but I can't log in as I type "ubuntu" for both login and password, it returns: "incorrect password". I have seen answers saying to try to ssh into the pi, but I don't get it as my Pi doesn't even have an fixed IP address. So my question is: how should I get over it ? I am completely blocked at that point.
I have also tried other versions as I would initially prefer ubuntu 18.04, but I wasn't able to find any desktop version, and the server version I found doesn't boot properly. My raspberry simply considers there is no SD card
Any help or hint would be much appreciated. Thank you very much