startx работает как root, но не как пользователь

Я очень новичок в Ubuntu (моя версия 18.04), и мне нужно запустить 'startx' от имени пользователя, не являющегося пользователем root, но мне выдается следующее сообщение об ошибке:

xauth:  timeout in locking authority file /run/user/1000/gdm/Xauthority
xauth:  timeout in locking authority file /run/user/1000/gdm/Xauthority


X.Org X Server 1.19.6
Release Date: 2017-12-20
X Protocol Version 11, Revision 0
Build Operating System: Linux 4.4.0-138-generic x86_64 Ubuntu
Current Operating System: Linux rzarrella-HP-350-G2 4.18.0-21-generic #22~18.04.1-Ubuntu SMP Thu May 16 15:07:19 UTC 2019 x86_64
Kernel command line: BOOT_IMAGE=/boot/vmlinuz-4.18.0-21-generic root=UUID=88e76656-6b6e-49bb-8858-32537ca86637 ro quiet splash vt.handoff=1
Build Date: 25 October 2018  04:11:27PM
xorg-server 2:1.19.6-1ubuntu4.2 (For technical support please see http://www.ubuntu.com/support) 
Current version of pixman: 0.34.0
Before reporting problems, check http://wiki.x.org
to make sure that you have the latest version.
Markers: (--) probed, (**) from config file, (==) default setting,
(++) from command line, (!!) notice, (II) informational,
(WW) warning, (EE) error, (NI) not implemented, (??) unknown.
(==) Log file: "/home/rzarrella/.local/share/xorg/Xorg.1.log", Time: Fri Jun  7 17:02:50 2019
(==) Using system config directory "/usr/share/X11/xorg.conf.d"
(EE) 
Fatal server error:
(EE) parse_vt_settings: Cannot open /dev/tty0 (Permission denied)
(EE) 
(EE) 
Please consult the The X.Org Foundation support 
 at http://wiki.x.org
 for help. 
(EE) Please also check the log file at "/home/rzarrella/.local/share/xorg/Xorg.1.log" for additional information.
(EE) 
(EE) Server terminated with error (1). Closing log file.
xinit: giving up
xinit: unable to connect to X server: Connection refused
xinit: server error
dpkg-reconfigurre xauth:  timeout in locking authority file /run/user/1000/gdm/Xauthority
Couldn't get a file descriptor referring to the console

Поскольку у меня нет Идея о том, как это исправить, мне действительно нужна помощь. Заранее спасибо!