debian 12 / xfce4 delete/remove the user uid 1000

I installed debian 12 / xfce4 desktop. I did something wrong and the user's xfce4 desktop was fully messed up. I tried to reinstall xfce4, anything, no way. I solved the problem with making a new user (uid 1002) with sudo privilegies and moved all files and settings to this new user. Now all is working without any problems. So I would like to remove the user (uid 1000). (user uid 1000 works well on terminal, the problems are only on the xfce4).
I would like to know whether anybody has a success when removing the user with uid 1000? As it is the initial user, I am afraid to have problems after.
Thanks for any ideas!