Carrying $ around ? Are those front chest like Fanny pack things ok?

Travelling to Rome/ Sorrento / Amalfi in late Sept. 2 weeks (Canadian).
We don't plan on bringing tons of $ but what do ppl use to carry funds / ID etc while out of hotel on day trips? Pickpockets can be a thing I hear. Safe to lock up passports and funds inside secure suitcase in hotel room? Do people use credit mostly??If going to a beach can valuables be left at your lounger if going in for a dip?? Am I paranoid??