Looks like someone's either forgotten to remove their collection, or passed away without telling their relatives where they'd hidden the coins.
Most of the ancients and mediaevals have more-or-less been identified for you.
#1: Roman empire, emperor Commodus. If it's "laureate head", then it'll be an as. Reverse has a seated figure with a shield and spear; looks most like Roma seated to me. So it should be something like
this example (except that's a sestertius, or 4-as coin). Listed in the Sear catalogue as number 5884, dated to 189 AD and this one probably has a value probably in the $30 to $60 range.
#2: Venetian Republic, silver grosso of Doge Antonio Venier (1382-1400 AD). In mediaeval times, Venice was one of the most powerful nations in Europe, and the "Doge" (the g is pronounced like a j; it's related to the English word "Duke") was the selected ruler. I don;t have a catalogue to value these coins properly.
#3: The portrait looks second century Roman, but the language might be Greek, making this a Roman Provincial coin. I'd really need to see the other side to tell you more.
#4: The Roman one is too well worn to tell much frm that picture (the other side might be more informative). The Venetian one is from the time of the Doge named on the 2x2.
#5: This one's a copper as from the Roman Republic, before the days of the Emperors. The obverse shows Janus, the Roman two-faced god after whom January was named; the reverse shows the prow of an ancient ship. These were struck It appears it's previous owner was unable to get a more accurate date than "sometime around 100 BC", and presumably made the photocopies / pictures to send to experts to help him identify it, back in the days before the Internet (aren't you lucky?

).
#6: The Venetian one is from the time of Doge Giovanni Soranzo (1312-1328). The others look like Late Roman bronzes, typically worth $5 to $10 each.
#7: This one's identified for you: Papal States, 1 baiocco 1748. In mediaeval and early modern times, right up to the unification of Italy in the 1860's, the Pope ruled a large slice of central Italy as a temporal prince, as well as his role as spiritual head of the church. In that sense, the Papal states can be seen as the precursor to the Vatican City (only the Papal States were much larger).
#8: Byzantine Empire, copper follis of emperor Justinian I. In the Byzantine monetary system, there were 40 nummi to a follis; the large "M" is the denomination mark - "M" is the Greek numeral for "40".
#9: a couple more Venetians, from the Doges named. "Billon" (not "billion") is a word that means "base-silver" - it contains silver, but it's not very pure. "tornesello" is the name of this small denomination.
#10: All the information you need is on the envelopes. The one on the left is a Roman Provincial coin from Antioch, the biblical city in what is now southern Turkey, during the time of emperor Vespasian. The one on the right is a "city commemorative" from the late Roman period, circa 330 AD. "Cyzicus" was a city in what is now north-western Turkey; the Romans had a mint there.
#11 has been done.
#12: there are numerous late Roman bronzes and similar coins here, like the ones mentioned at 6. The larger ones appear to be earlier Roman bronzes; we'd need to see the other sides to identify them properly.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis