Best train lines from Milan to Como

You might want to look at taking the bus, it should be faster than a train. I don't understand your question "what train line" ? J

Milan or Como or both??????

Does your lodging host not know which station is closest?

For a 30 mile trip I would choose by price.

Almost all trains from Milano Centrale train station to Como are operated by Milan’s regional transport company called Trenord. Tickets for those trains are about €5 and the trip takes about one hour.
For €16 you can shave twenty minutes off the trip and take one of the very few Trenitalia trains.
www.TheTrainline.com

Trenitalia sells Trenord tickets

https://www.trenitalia.com/content/tcom/en.html

There are 2 stations in Como, Como San Giovanni is on the side of the hill west of the city center, and Como Lago on the lake front in the city center. Trains to Como S. Giovanni go from Milano Centrale station, and trains to Como Lago go from Milano Cadorna station. Take your pick.

There are two train lines from Milan to Como. The former "state" train line goes from main stations of Milan (Centrale and Porta Garibaldi) to Monza and Como San Giovanni. This line is part of the longer Gotthard route to Switzerland, so has long range and international trains run by Trenitalia, as well as commuter trains run by Trenord and the medium range international services to Ticino run by Tilo.

There is also the former "Ferrovie Nord" commuter route from Milano Cadorna to Saronno and Como Lago, once separate and unconnected to the main network, now connected to the underground "passante" line under central Milan and run as part of the regional network. This line has only slow commuter services, so does not qualify as "best", but leaves from more central stations in Milano and Como - the one in Como is close to the ferry pier while San Giovanni is up the mountain.

Thank you all SO much - this is very helpful!