Via dei Condotti is where posh shops are( you might also try on Cola di Rienzi ). Enter from piazza di Spagna, with its famous steps(subway station) and finish on via del Corso. Go to left and in short you’ll see the famous quadrighe(four horses carts) on top of Il Vittoriano, the monument dedicated to Vittorio Emanuele II, first king of Italy; via del Corso steps out into famous piazza Venezia with its continuous and fascinating chaos of cars, busses and tourists troops. With cameras; have yours on. Selfie stick on street sellers(10 euros).
might want a slice of pizza while you’re at it