Ruby
How are you getting to Liverpool?
Will you have a car in England, and would you consider visiting Stonehenge from london by tour bus? Or train to Salisbury then tour bus?
There is no such thing as a "Europass". There is a "Eurailpass" discussed at quite long lengths here.
For a few specifics related to your proposed trip,
You list
Liverpool
Stonehenge
London
Paris
Rome
Florence
Cinque Terre
Barcelona
Granada
Madrid
which I count as 10 cities or areas. So your trip will be at least 30 nights plus long distance transportation, is that right? That's pretty long for a first trip.
What time of year is this trip?
Are returning home from Madrid? Flying direct, or via another city?
Liverpool to Stonehenge
Train to London and tour bus or car or train to Salisbury and taxi or tour bus or car.
Stonehenge to London
Retrace to London or Salisbury. If Salisbury, train to London, buy in advance.
London to Paris
Eurostar - buy far in advance, prices never go down.
Paris to Rome
Fly. Train is very long and flying is almost certainly much cheaper.
Rome to Florence
High speed train. One of your shortest journeys. Tickets well in advance can be very cheap, but they go quickly. Prices never go down, but as cheaper tickets sell out they most definitely go up.
Florence to Cinque Terre
Slow train.
All this time and no Venice? Oh my.
Cinque Terre to Barcelona
My goodness, that's a tough one. Train definitely won't work unless you want to take up residence on all the trains involved. Fly. Either Pisa or Genova. Neither one is trivial. The Cinque Terre is a bit remote.
Barcelona to Granada to Madrid.
I have no idea about Spain, but I do know that distances are long and that long distance buses, trains and planes are plentiful in Spain.
That's some first trip. I really, really, really hope you have enough nights on this trip to do it justice and you not to die trying....