Money. The currency is the Zambian Kwacha (ZMW). ATMs are widely available in Lusaka, Livingstone, and larger towns, and most accept international Visa cards. Mastercard is less reliably accepted. US dollars are widely used for safari lodges, national park fees, and tourist activities -- bring clean, undamaged notes printed after 2006. Mobile money (Airtel Money and MTN MoMo) is how most Zambians pay for things, but it is not very practical for visitors. Credit cards work at upmarket hotels and restaurants but not at markets or small shops. Always carry some Kwacha in cash for everyday purchases.
Language. English is the official language and is spoken widely in cities and tourist areas. In rural Zambia, you may need a few words of the local language. The two most useful are Nyanja (dominant in Lusaka and the east) and Bemba (dominant in the north and Copperbelt). Basic greetings go a long way -- see the People section for useful phrases.
Safety. Zambia is one of the safest countries in southern Africa. Violent crime against tourists is rare, but petty theft happens in cities, particularly in Lusaka. Keep valuables out of sight, avoid walking alone at night in urban areas, and be alert at markets and bus stations. Outside the cities, the main risks are road conditions rather than crime.
Health. Zambia is a malaria zone. Take prophylaxis, sleep under a treated mosquito net, and use repellent. The risk is highest during and just after the rains (November to April) and lower in the dry season. Tap water is not safe to drink outside major hotels -- stick to bottled or purified water. Medical facilities in Lusaka are adequate for basic care, but for anything serious you would want evacuation to South Africa. Travel insurance with medical evacuation cover is essential.
Communications. Buy a local SIM card on arrival -- Airtel and MTN have the best coverage. Data is cheap and 4G works in cities and towns. In remote bush camps and national parks, do not count on any signal at all. Wi-Fi is available at most hotels and lodges but can be slow.
Electricity. Zambia uses British-style three-pin plugs (Type G) at 230V. Load shedding (planned power cuts) happens, especially during drought years when the hydroelectric dams at Kariba run low. Safari lodges typically have generators or solar backup.