No, we should not get involved in this conflict

Russia's expansionism poses a pretty direct threat to NATO, the EU, and to Germany. It seems reasonably likely that if Putin is successful in Ukraine, this will strengthen his regime and embolden him to continue engaging in "Special Military Operations" with his other neighbors. For instance, it seems probable that he would consider invading Georgia again. Given that Georgia wants to join the EU, this would be an issue. Generally, Russia winning in Ukraine would embolden it to damage European security and fight against German interests.