Little Italy has changed a great deal in the last 50 years. The San Gennaro festival now includes many street cuisines other than Italian.
There are still some great restaurants and bakeries.
My hands-down favorite for many years is Il Cortile, on Mulberry. Elegant, old-world service; terrific food and great ambiance. Ask for a table in the back, with the "garden" and statues. BTW, it ain’t cheap.
LUNA, across the street diagonally, is a good look at what the scene used to be, but the food has not been very good for a long time.
I also like Da Nico, down the block.
Most of the bakeries do it all, and well; the old reliable is still Ferrara’s. Around the holidays (and festas)look for the fig cookies.
I agree that comfortable shoes are a must; take it slowly, and wander around. There is always something new to discover in NYC.