Possible itineraries
Here are some ways you can structure a three or four day trip
Day 1 arrive Ouistreham on overnight ferry
OR come the day before, arriving 10pm and stay in Ouistreham
Cycle to Caen (9 miles) in the morning, stopping off there for two or three hours.
Cycle to Clecy (25 miles) in the afternoon
Day 2 Walking in the Suisse Normande
Day 3 Return to Ouistreham, taking late afternoon or overnight ferry.
4 days, Ouistreham, Clecy, Beyeux, Normandy beaches
Days 1 and 2 as in 3-day version
Day 3 Clecy to Bayeux (about 35 miles)
Day 4 Bayeux to Ouistreham via D-day beaches to take evening or afternoon ferry (26 miles).
NB. When planning, you might want to take account of the fact that Thury Harcourt, about 8 miles north of Clecy, has a nice market on Tuesdays - nice for a stop-off and useful for buying a picnic lunch. If you go to Bayeux, there are a couple of towns on the way with markets: Villers Bocage on Wednesday, and Aunay sur Odon on Saturday.
Here is a map for general orientation. I've also included maps on individual sections.