Nach in Konflikt stehenden Paketen wird gesucht …
:: libreoffice-fresh-26.2.4-1.1 and libreoffice-still-25.8.7-2.1 are in conflict
Fehler: Nicht auflösbare Paketkonflikte gefunden
Fehler: Vorgang konnte nicht vorbereitet werden (In Konflikt stehende Abhängigkeiten)
There can be only one.
You need to choose still or fresh.
What preceded those outputs?
What commands and responses to prompts?
As mentioned above, if attempting to install either libreoffice-fresh or libreoffice-still you must accept replacing the other and not attempt to mix them.
It may also be worth repeating that one needs to be refreshed and synced before installing new software and that we do not do that without upgrading.
So all of that together means a full attempt might look like;
sudo pacman -Syu libreoffice-fresh
During which any replacements must be accepted or else the transaction will not complete.