Advice on visiting Normandy, France.

I will be visiting Europe for a month this summer and am planning on visiting Normandy for 2 days.
I really want to see Omaha and Juno beach, as well as the Caen Memorial Museum. From what I have read, the best ways of seeing all 3 is to rent a car or pay for day tours, however I am not old enough to rent a car in France and the day tours are crazy expensive. Has anyone visited these places another way? I know there are buses, but it does not look like they run very late, and according to google maps, walking to Omaha from the Bayeux train station is around 3 hours, as is walking from the Caen Memorial Museum to the Juno Beach Centre. Based on the experience of anyone who has visited, would it be more advisable to pay for day tours, or take the bus and/or walk?

Advice on visiting Normandy, France.