What cultural faux pas should I try to avoid making in Ljubljana?

"It is important to be mindful of local customs and etiquette when visiting Ljubljana. It is considered rude to be late for appointments or social engagements, so it is important to arrive on time. It is also important to dress modestly and conservatively, as revealing clothing is considered inappropriate. Additionally, it is important to be respectful of religious sites and to avoid taking photographs without permission. Finally, it is important to be aware of the local language and to avoid speaking loudly in public," remarked another expat who made the move to Ljubljana, Slovenia.