good thing is we are only doing checked baggage, buy train ticket, and head to milan cintrale and check our luggage in and RUN to meet tour. UGH!!
2nd part of question. is it best to buy train ticket upon arrival? or since we dont know exactly time we would be avail for departure to purchase then? where is quickest place/way to get tickets upon arrival?
If you will be arriving at Malpensa Airport, you will need to take the 'Malpensa Express' train to Milano Centrale (buy tickets at the ticket window next to train tracks. Travel time is about 52 minutes.
Once you arrive to Milano Centrale, follow signs to 'Deposito baggagli'(left luggage), located on ground floor (take escalator down)
see more info here: http://www.milanocentrale.it/en/service/detail/left-luggage1
There may be a line at the luggage storage office...
Here is a map of Milano Centrale:http://www.milanocentrale.it/en/map/
I'd recommend taking a taxi from Milano Centrale to the Church of Santa Maria delle Grazie (site of The Last Supper masterpiece)
You can also take the Metro from Milano Centrale to Cadorna station (very close to above church), but since you may be rushing, a taxi may be your best option.
Keep in mind that you need to arrive at least 20 minutes prior to your reservation time.
You can always return to the train station after visiting the Last Supper where you can purchase your train tickets for your next destination.
You can purchase them at the ticket office or at a self-service ticket machine, see this website for more information:
http://www.seat61.com/Italy-trains.htm#Self-service_ticket_machines
Have a wonderful trip!