In American blogs you can read that they have travelled the Cinque Terre in one day only.
What a shame!
Of course, you can do it but they will have missed so much.
To experience Cinque Terre (one of the most beautiful walking areas) you need to spend some days.
Here is what I would suggest:
Best is not to walk from accommodation to accommodation because there are not many places and the ones which are there will not accept one night stays. But the five villages clinging to steep slopes at the seaside can only be reached by walking or by train but hardly by car and this only on cul de sacs with little parking possibilities.
Therefore my suggestion is (and this is what most people do) to find a base camp/hotel/hostel. Many tourists choose for this reason the town Levanto. But this is very busy, overpriced because of that choice. It is therefore better to choose Sestri Levante, further north, a very nice town with a historic town centre but with various accommodations of all categories for every budget.
And as all the villages along the coast have a train station you can use this means of transport to organize your walks. The train rides are regular and cheap. Best is to start with the most southern village and walk north with the sun in your back.
There are pathes on different high levels you can choose from.
Day 1: Riomaggiore to Corniglia via Manarola (this you can do on a path next to the sea / but later it is nicer to use the higher pathes from Manarola to Corniglia) with stunning views and passing the village Volastra
Day 2: Corniglia to Vernazza
Day 3: Vernazza to Monterosso al Mare
Day 4: Monterosso al Mare to Levanto
Day 5: from Riva Trigoso to Moneglia (a walk through a nature reserve - this is a must)
Another highlight you should not miss is the following trip!
Day 6: from Santa Margherita Ligure to San Fruttuoso (a monastery) to Portofino (a trip north of Sestri Levante)
You can take the train to S.M.L. walk to the monastery San Fruttuoso (it can only be reached by walking or with a boat) which has a restaurant and a little pebble beach for a rest and continue your walk to the scenic little harbour town “Portofino”. From there you can either walk along the coast (a lot of the path is along the road) or better take a bus or the boat back to S.M.L.!
(All the walks can be easily done in a day, with rests included - setting off from the accommodation in Sestri Levante at 10a.m.)