EURO TRIP SUGGESTION + Guidance!!

Hey guys,

My girlfriend and I are taking our first euro trip together in the end of may of 2026, considering the worlds about to end so why not? lol
we are planning to do Paris - Belgium - Rome and back home in a span of 10 days. I want suggestions on things that we must absolutely not miss out / do, any local cafes/thrift stores/food places we must try, and the gimmecks we must skip. and if you have any suggestions for any cheap accomodations