Trouble login to desktop

I am having trouble logging in to my desktop. When I type in my password it goes to the black screen and says:

/dev/sda1: clean , 330744/61054976 files 687396/244189752 blocks

I am able to login into TTY and key in my user and password. I had a go with

sudo pacman -Syu`

the system says
error: failed retrieving file ‘core.db’ from a long list of mirrors host.

All I did before this happens was trying to rename my hostname, username, and disabling the KDE wallet from popping whenever I login.

I will appreciate if someone in this community can guide me through this problem without reinstalling the system.

I mean, when Manjaro starts, message like

/dev/sda1: clean , 330744/61054976 files 687396/244189752 blocks

usually appears.
To me this looks like a GUI crash.

If sudo pacman -Syu gave you error: failed retrieving file ‘core.db’, I think you should check your internet connection and/or try sudo pacman -Sy