Hi, you can easily get to Malcesine by car in time to take the cable car up to Monte Baldo, and there are some lovely walks up there. Information on times and ticket prices is at
www.funiviamalcesine.com
There are two car ferries on the lake; one from Malcesine to Limone and the other from Torri del Benaco to Toscolano/Maderno.
You don't say which month you plan to visit which could have some bearing on how busy the traffic is on the lake roads and if you want to drive. If you don't want to use your car then you could take a bus from Verona to Malcesine. The timetable is on
www.apt.vr.it/pdf/62-64.pdf
The largest beach on the lake is at Riva although most places have a beach area.
One other thing worth mentioning - you said that you will be in Verona for a long weekend. If you have the whole of the Monday then that would be the best time to take a day trip to the lake. The monuments, museums etc in Verona are closed on Mondays until early afternoon.