How to use switzerland train sites Luzern to Como Italy for example

It's sbb.ch/en and you simply type in your starting destination in the "From" section and your end destination in the "To" along with your date and it will show you all the options for that route. Your trips for Como to Venice and Milan will be through Trenitalia (Italy's train system), not SBB (Switzerland's train system).

The simplest connection from Luzern to Como Nord Lago is 3 hr 45 min with 1 stop in Arth-Goldau and departs every hour on the :39. And to clarify your "(aka Lucerne?)" comment, the German spelling of the town is Luzern, which is what SBB uses.

I'm not clear what exactly you're confused about, so perhaps you could clarify what specific questions you have.

The simplest connection from Luzern to Como Nord Lago is 3 hr 45 min

The train actually stops at Como San Giovanni station, then suggests a 16 minute walk to Nord Lago on the water front.

Use http://www.trenitalia.com/tcom-en for trains from Como to Venice and back to Milan. Venice is Venezia and Milan is Milano. The Trenitalia site is picky about names, insisting you use Italian City names.

in particular, Venice has several stations, the main one on the island (Venezia SL or Venezia Santa Lucia (Saint Lucy in English but the English name is not used), probably the one you want), the main one on the mainland (Venezia Mestre, which you probably don't want) and a couple of very minor ones which you definitely don't want.

Different cities are spelled and pronounced differently in different languages, like London is Londres in Spanish and French.

Luzern is in the German language region of Switzerland so that is the proper spelling. Lucerne is the English translation. Luzerne in French.

There are two train lines next to Lake Como. The one discussed above goes under the bottom of the lake; there is also a line up the east side between Milan (Milano Centrale) through Varenna, a popular jumping off point for the mid-lake (and beautiful) all the way up to the Swiss border at Tirano, where the Bernina train line starts.

It would be helpful to know your actual destination on the lake so we could give you a much more precise answer. You may need a boat or a bus.

First of all, thanks for the speedy replies. This is a great resource and I hope to help others when I can to return the courtesy.
In my post I mistyped the swiss site which is sub.ch/en so I was looking at the correct one. I will use your instructions and try again.
We are traveling by train from Basel to Luzern with that portion figured out and I am working on the best /scenic route to Lake Como and then through Verona to Venice for a couple nights then to Milan to fly back to California.
Any suggestions would be greatly appreciated. I was trying to figure out if we could incorporate part of the route of the Glacier express by taking the boat down Lake Luzern and catch the Gotthard train or a local train towhere the Glacier express train(s) head up to St. Moritz and the Bernina express or local train(s) to Tirano and then train or bus? to Lake Como, maybe stay in Varenna, Bellagio or Como town? We will spend 1 or more nights at wherever makes sense and end up heading for 2 nights in Venice then to Milan for the fklight home. That is the general outline so far. We are 2 70 year old couples travelling together.
Any ideas or different/better routes will be appreciated.