train route

Total depends on the route. Check your train schedule and there should a place to expand or give details on that route and will list the stops. Sometimes it is a little + sign in the corner. It will vary. Which web site are you using for the schedule or routing?

Not sure what you mean by a "layover". If you mean changing trains, you will do that more than once, you cannot get from Milan to Frankfurt on the same train.

You can look this up on the DB website: https://www.bahn.com/en/view/index.shtml
Once you have selected an option, expand once for a list of all trains and places where you change trains. Click again on a train number for a list of stops. There is also a map option.

A typical set of trains is (there are others):

Train FR 9708
Venezia Santa Lucia dep 07:20
Venezia Mestre dep 07:32
Padova arr 07:46 dep 07:48
Vicenza arr 08:03 dep 08:05
Verona Porta Nuova arr 08:30 dep 08:32
Peschiera del Garda arr 08:46 dep 08:48
Brescia arr 09:07 dep 09:09
Milano Centrale arr 09:45

Train EC 158
Milano Centrale dep 10:15
Como S. Giovanni arr 10:59 dep 11:01
Chiasso arr 11:10 dep 11:15
Lugano arr 11:38 dep 11:43
Bellinzona arr 12:10 dep 12:13
Arth-Goldau arr 13:09 dep 13:14
Luzern arr 13:41 dep 13:54
Olten arr 14:27 dep 14:30
Basel SBB arr 14:55

Train ICE 70
Basel SBB arr 14:53 dep 15:06
Basel Bad Bf arr 15:12 dep 15:15
Freiburg(Breisgau) Hbf arr 15:47 dep 15:49
Baden-Baden arr 16:35 dep 16:37
Karlsruhe Hbf arr 16:51 dep 16:53
Mannheim Hbf arr 17:15 dep 17:17
Frankfurt(Main)Hbf arr 17:52 dep 17:58
Kassel-Wilhelmshöhe arr 19:19 dep 19:21
Göttingen arr 19:38 dep 19:40
Hannover Messe/Laatzen arr 20:16 dep 20:19
Hamburg-Harburg arr 21:42
Hamburg Hbf arr 21:54
Hamburg Dammtor arr 22:02
Hamburg-Altona arr 22:12

Sorry, not layover, but change trains. Our itinerary says: Venezia S. Lucia - Milano Centrale , Train Frecciarossa 9714, then Milano Centrale - Frankfurt , Train EuroCity 52. It doesn't indicate another trainchange from Milano to Frankfurt. Am I missing something here? I booked through Rick Steve's Rail Europe. Thanks for all your help.

New this year there is one train per day direct (no changes) from Milan to Frankfurt. You didn't give a time or a date, so I couldn't tell which train you were talking about.
You can look it all up on the DB website: https://www.bahn.com/en/view/index.shtml
For a random date in May, I found this:

Train FR 9714
Venezia Santa Lucia dep 08:20
Venezia Mestre dep 08:32
Padova arr 08:46 dep 08:48
Vicenza arr 09:03 dep 09:05
Verona Porta Nuova arr 09:30 dep 09:32
Peschiera del Garda arr 09:45 dep 09:47
Brescia arr 10:07 dep 10:09
Milano Centrale arr 10:45 dep 10:55
Torino Porta Susa arr 11:43
Torino Porta Nuova arr 11:55

Train EC 52
Milano Centrale dep 11:23
Stresa arr 12:19 dep 12:21
Domodossola arr 12:43 dep 12:48
Brig arr 13:16 dep 13:19
Visp arr 13:25 dep 13:28
Spiez arr 13:53 dep 13:54
Thun arr 14:03 dep 14:04
Bern arr 14:24 dep 14:36
Olten arr 15:03 dep 15:05
Basel SBB arr 15:29 dep 15:38
Basel Bad Bf arr 15:44 dep 15:52
Freiburg(Breisgau) Hbf arr 16:20 dep 16:22
Karlsruhe Hbf arr 17:29 dep 17:31
Mannheim Hbf arr 18:10 dep 18:12
Frankfurt(Main)Hbf arr 18:59

Is this the info you wanted?

BTW, saying "Frankfurt, Germany" is ambiguous. There are TWO Frankfurt's, both in Germany:
Frankfurt am Main
Frankfurt an der Oder.

Yes, thanks Cris.