Milán AirPort to train station?

Malpensa airport? Take the airport train to Milano Centrale and then another one to SML. If you are flying in either Linate or Bergamo airports, take a bus to Milano Centrale and then a train etc.
Train schedules and tickets before December 10 on www.trenitalia.com

And if you are on an NYC to Milan nonstop, you'll land at Malpensa. Train station right at the airport. It has trains going to two different stations in Milan on an alternating 15 minute schedule. Make sure you get on the train to Milano Centrale, where you can connect to trains going anywhere in Italy.

Susan,
In case you need a bit more info: In the Milan airport, you will need to descend a couple of levels to the trains. Look for signs for "trains".
You want the Malpensa Express (not an express!!). The train goes from the airport to the central train station with stops in between and then back out to the airport again. Go to the end of the line. Make sure you have some Euros with you to purchase tickets from the machine. Instructions on the machine are straightforward. Once the ticket(s) are purchased, there is a small blue and white machine there that you will need to insert your ticket into. This is validating the ticket. DON'T FORGET THIS PART! There are luggage racks in each car. I like to sit as near the racks as possible so I can keep an eye on my bag.

Once in the central train station, it is easy to purchase tickets from the automated machines with Euros or credit card. Click the English icon and just follow instructions. Really easy but DO NOT accept assistance from anyone who casually comes up to you and asks if you need help unless they are wearing Trentitalia uniforms. The "helper" will expect some small payment for their "assistance". Once you have your ticket with the time of the train, just look at the boards to find which track. Everything is very well signed. Depending on the type of train you are on (check when booking seat) you may need to validate this ticket. Unless you have a specific car number and seat assignment, you will need to validate. This is done with orange/white boxes located all around the train station. Regionalle trains always need validation prior to boarding.

Unless you really need assistance in getting you and your bags onto the train, don't accept the casual offer to help. The "helper" will want money to do so but only after "helping" you. It is oh-so-easy to accept the assistance without being aware of the "fee" especially if jet-lagged. The train personnel do not offer this service. You will be expected to manage your own bags.

I'd get both tickets at Malpensa station.
There is no reason to make 2 separate purchases.
At Centrale this would also mean that you should exit the tracks area and look for the ticket machines/counters. Milano Centrale is huge, Imho this an awful advice for somebody who has luggage to drag.

Take the Malpensa Express to Centrale, not the one to Cadorna.
Here is a network map showing all intermediate stops: www.malpensaexpress.it

Incidentally, you must time-stamp only the regional regional trains tickets not purchased online. There are authorized luggage porters at Milano Centrale wearing an obvious uniform.

darioalb. Thank you for the info. I have one other question, can you buy the tickets for Malpensa Express to Milan Centrale using a credit/ATM card. On another note, I have downloaded the trenit app, with the plans of buying my ticket from Milan Centrale to my next destination when I arrive in Italy. Just an idea for the OP.

If you have a contactless credit card you just swipe it to open the turnstiles, you don't actually purchase tickets anymore.

I've never heard of a manned counter not taking ATM/credit cards, whereas there are automatic machines that accept only cash and others that want only plastics. I'm sure there are both at MXP, but the latter type of machines may ask for chip&pin cards.

Since there is free wifi at the airport I usually buy both my malpensa express and trenitalia tickets online, while waiting for my bags. Trenitalia.com sells also the malpensa express tickets: just enter "Malpensa Aeroporto" as departure station and Santa Margherita Ligure-Portofino in the "to" box.
Online seems easier and quicker, but I use an indipendent app that lets me compare trenitalia and italotreno prices at a glance. Unfortunately you're visiting a Region not yet blessed by railway competition.