To update packages, run
pacman -Syu
To install a software, run
pacman -S PKG_NAME
To search for a package
pacman -Ss PKG_NAME
Show information about a specific package
pacman -Si PKG_NAME
To get list of all files installed by a package
pacman -Fl PKG_NAME pacman -Ql PKG_NAME
To verify presence of all files installed by a package
pacman -Qk PKG_NAME
To find which package provide a file
pacman -Fsy FILE_NAME
Example
[root@PAR-139278 ~]# pacman -Fsy apachectl
:: Synchronizing package databases...
core is up to date
extra is up to date
community is up to date
extra/apache 2.4.39-1
usr/bin/apachectl
[root@PAR-139278 ~]#