As quick solution, you can find the <span> for the rooms, and then use find_next for surface and again, find_next for the number of toilets:
For example (also I used get_text(strip=True) to strip the text of whitespaces):
for item in listing_content:
#Store info to a dictionary
web_content_dict = {}
web_content_dict["Title"] = item.find("p",{"class":"titolo text-primary"}).find("a").get("title")
web_content_dict["Price"] = item.find("li",{"class":"lif__item lif__pricing"}).get_text(strip=True)
web_content_dict["Rooms"] = item.find("span",{"class":"text-bold"}).get_text(strip=True)
web_content_dict["Surface"] = item.find("span",{"class":"text-bold"}).find_next("span").get_text(strip=True)
web_content_dict["Toilets"] = item.find("span",{"class":"text-bold"}).find_next("span").find_next("span").get_text(strip=True)
When I printed the variable web_content_dict, it was like this:
{'Title': "Bilocale via Fra' Giovanni Pantaleo 3, Bovisa, Milano", 'Price': '€ 187.000', 'Rooms': '2', 'Surface': '65', 'Toilets': '1'}
{'Title': 'Trilocale via Monte Rosa 15, Amendola - Buonarroti, Milano', 'Price': '€ 730.000', 'Rooms': '3', 'Surface': '140', 'Toilets': '2'}
{'Title': 'Trilocale via San Senatore, 2, Missori, Milano', 'Price': '€ 665.000', 'Rooms': '3', 'Surface': '109', 'Toilets': '2'}
{'Title': 'Quadrilocale viale Duilio 6, Sempione, Milano', 'Price': '€ 1.150.000', 'Rooms': '4', 'Surface': '165', 'Toilets': '2'}
{'Title': "Appartamento piazza Sant'agostino, 6, Corso Genova, Milano", 'Price': '€ 1.650.000', 'Rooms': '5', 'Surface': '275', 'Toilets': '3+'}
{'Title': 'Trilocale via Val Gardena 25, Precotto, Milano', 'Price': '€ 170.000', 'Rooms': '3', 'Surface': '91', 'Toilets': '1'}
{'Title': 'Appartamento corso Di Porta Nuova, Turati, Milano', 'Price': '€ 1.130.000', 'Rooms': '5+', 'Surface': '210', 'Toilets': '3'}
{'Title': 'Trilocale via Francesco Albani 58, Monte Rosa - Lotto, Milano', 'Price': '€ 380.000', 'Rooms': '3', 'Surface': '90', 'Toilets': '1'}
{'Title': 'Bilocale via Antonio Cesari 47, Niguarda, Milano', 'Price': '€ 115.000', 'Rooms': '2', 'Surface': '46', 'Toilets': '1'}
{'Title': 'Trilocale via mazzucotelli 15, Quartiere Forlanini, Milano', 'Price': '€ 215.000', 'Rooms': '3', 'Surface': '91', 'Toilets': '2'}
{'Title': 'Bilocale via Livorno, Palestro, Milano', 'Price': '€ 520.000', 'Rooms': '2', 'Surface': '57', 'Toilets': '1'}
{'Title': 'Bilocale via Maspero 28, Molise - Cuoco, Milano', 'Price': '€ 290.000', 'Rooms': '2', 'Surface': '70', 'Toilets': '1'}
{'Title': 'Trilocale largo Gemito, 3, Casoretto, Milano', 'Price': '€ 308.000', 'Rooms': '3', 'Surface': '93', 'Toilets': '1'}
{'Title': 'Quadrilocale via Pietro Paleocapa, Cadorna - Castello, Milano', 'Price': '€ 1.300.000', 'Rooms': '4', 'Surface': '180', 'Toilets': '3'}
{'Title': 'Bilocale via Renato Fucini, Città Studi, Milano', 'Price': '€ 511.000', 'Rooms': '2', 'Surface': '85', 'Toilets': '1'}
{'Title': 'Quadrilocale via Lucca, Bisceglie, Milano', 'Price': '€ 275.000', 'Rooms': '4', 'Surface': '100', 'Toilets': '1'}
{'Title': 'Trilocale via RIZZARDI 45, Trenno, Milano', 'Price': '€ 485.000', 'Rooms': '3', 'Surface': '127', 'Toilets': '1'}
{'Title': 'Bilocale via bacchiglione, Corvetto, Milano', 'Price': '€ 220.000', 'Rooms': '2', 'Surface': '50', 'Toilets': '1'}
{'Title': 'Quadrilocale via Cadore, Cadore, Milano', 'Price': '€ 1.060.000', 'Rooms': '4', 'Surface': '210', 'Toilets': '2'}
{'Title': 'Bilocale via bacchiglione, Corvetto, Milano', 'Price': '€ 195.000', 'Rooms': '2', 'Surface': '42', 'Toilets': '1'}
{'Title': 'Bilocale buono stato, primo piano, Brera, Milano', 'Price': '€ 800.000', 'Rooms': '2', 'Surface': '87', 'Toilets': '2'}
{'Title': 'Trilocale via bacchiglione, Corvetto, Milano', 'Price': '€ 540.000', 'Rooms': '3', 'Surface': '120', 'Toilets': '2'}
{'Title': 'Bilocale via bacchiglione, Corvetto, Milano', 'Price': '€ 350.000', 'Rooms': '2', 'Surface': '81', 'Toilets': '1'}
{'Title': 'Bilocale via bacchiglione, Corvetto, Milano', 'Price': '€ 265.000', 'Rooms': '2', 'Surface': '50', 'Toilets': '1'}
{'Title': 'Appartamento via Antonio Pianella, 4, San Siro, Milano', 'Price': '€ 649.000', 'Rooms': '5+', 'Surface': '150', 'Toilets': '3'}