Do French train stations have lockers?

We will be traveling to France and are thinking of taking a train to Rouen, exploring the city and then finding a hotel to stay at overnight and explore more of Normandy by rental car for the rest of the week (we already have a hotel for the rest of the time we are there). We are not backpackers but have a carry-on each. Do the train stations have lockers to store carry-on luggage? Also, in the month of July, would it be wiser to get a hotel reservation and rental car ahead of time?