Rental Car options near Lake Garda

www.autoeurope.com (a broker consolidator that offers deals with major rental companies in Europe, like Europcar, Hertz, Avis etc.
Rental car pick up could be at Milan airport (Malpensa airport, I suppose) where you land, or if you want closer to Lake Garda, then select Verona. Most rental car agencies in Verona are not far from the train station, as well as at the Verona airport, which however it's out of town near the town of Villafranca.
Your car rental return would be at Treviso (either in the city or at the Treviso airport).
The drive from the Malpensa airport to lake Garda is approximately 2.5 hours, depending on traffic and exact town on the lake. The drive from Verona to the lake is about 30 to 60 minutes depending on where on the lake you want to go.
If you decide to take the train to Verona, assuming you land at Milan Malpensa, you take the Malpensa Express train from the airport to the MILANO CENTRALE train station. Then from Milano Centrale you would take a train to VERONA PORTA NUOVA (most likely the train would be headed to Venice or Trieste, with Verona being an intermediate stop).
For train timetables consult:
www.trenitalia.com
from: MALPENSA AEROPORTO
to: VERONA PORTA NUOVA

I'm wanting to not travel as far east as Verona if possible. may not have an option that works better than just renting from milan.

Since you plan to rent a car anyhow on the day you arrive, in your shoes I would rent directly at the Malpensa airport and drive the 200 km to lake Garda. I realize that renting at the airport has some extra airport rental fees but the price difference is probably not worth the hassle of changing two trains (with luggage). Also the train cost you'd need to incur would negate any savings of renting the car in a city rather than the airport, especially because, aside from Verona or Milan, all other locations along the way are not near the respective train station so you'd need to take a taxi from the station to the rental agency as well, adding extra cost. I don't recommend to take the train to Milan and renting the car at the Milan train station, because of the traffic hassle getting out of the city and back to the freeway. So if Verona is not suitable to you, rent at the airport where you land.

we are not renting the day we land, doing so the next day. sorry that was not super clear. we rented a car and drove out of rome once and it was somewhat stressful. thought we might try and avoid the urban traffic.

If you don’t rent a car on the day of arrival where do you plan to spend the first night after you land then? Knowing where you’ll be the morning after would help us determine the best place to rent a car. Also where on the lake do you plan to stay?

we are staying the central part of milan near the cathedral for one night (5/15) then going to travel to ortisei in the dolomites.
thanks for the assistance and i clearly did not provide enough info in my original post. cd