Level 1 is the same rating the State Department gives most of Western Europe. The advisory does not single out any region, and the border with Belarus and Ukraine, a few hundred miles east of the pilgrimage cities, carries no separate travel restriction in the advisory text; Poland is a NATO and EU member, and the war in Ukraine has not changed its rating. U.S. citizens enter without a visa for up to 90 days in the Schengen area, with a passport valid at least three months beyond departure.
In practice the issues pilgrims report are small. Kraków's main square and the Royal Route draw pickpockets at busy times; use the hotel safe and carry a copy of the passport. Take taxis from marked ranks or an app rather than from a stranger at the station. Alcohol is sold everywhere and public drunkenness around the Old Town on weekend nights is the most visible disorder. Tap water is drinkable; pharmacies are plentiful; emergency number 112 works with English operators.
Poland is a Catholic country where pilgrim groups are normal, and Jasna Góra, Łagiewniki and Wadowice are staffed for foreign visitors. The one place that needs extra sensitivity rather than caution is Auschwitz, where the Memorial asks for solemnity and bans photography in some blocks. Conditions can change; the advisory page and the U.S. Embassy in Warsaw carry any updates, and enrolling in the free STEP program delivers alerts by email.