Should I buy a rail pass?

Usually no. For a 14-day trip with only 3-4 destinations, point-to-point tickets bought in advance are almost always cheaper than a Eurail pass.

How much cash do I need?

Very little. Europe is largely card-based now. Keep €50 in small bills for emergencies, but you can pay for almost everything with a contactless card or phone.

Planning a Two-Week First Trip to Europe

Limit yourself to three major cities connected by high-speed rail to avoid spending your entire trip in transit. Focus on a single region, such as the UK-France-Netherlands corridor or the Italy-Central Europe circuit, to minimize travel fatigue.

Pick one geographical theme. Don't try to cover London, Paris, Rome, and Berlin in 14 days. Choose a cluster. For example: London (3 days) -> Paris (4 days) -> Amsterdam (3 days) works perfectly via the Eurostar train.
Use the 3-4-3-4 rule. Allocate 3 or 4 nights per city. This gives you at least 2 full days of sightseeing in each place, plus a buffer day for transit or spontaneous discovery.
Prioritize high-speed rail. Europe’s train network is far superior to budget airlines. Use sites like Trainline or Omio to book trains between city centers. This saves you the 4-hour time block required for airport security and commute.
Limit your 'must-see' list. Pick one major landmark per day (e.g., The Louvre, The Colosseum). Fill the rest of your day with walking, eating, and observing. Over-scheduling is the quickest way to burn out by day 7.

Should I buy a rail pass?: Usually no. For a 14-day trip with only 3-4 destinations, point-to-point tickets bought in advance are almost always cheaper than a Eurail pass.
How much cash do I need?: Very little. Europe is largely card-based now. Keep €50 in small bills for emergencies, but you can pay for almost everything with a contactless card or phone.