Help choosing a country for a short trip for May with my best friend

Planning a short Europe trip for May with my best friend (both 24M).

We’re looking for:

- lively atmosphere (not quiet before summer)

- good nightlife / young vibe

- affordable shopping & sales

- nice scenery and walkable cities

For context: I’ve only been to Europe twice, both times to Prague — and I absolutely loved it. The vibe, prices, walkability, nightlife… pretty much everything. So something with a similar energy would be great.

Trip length: around 4–6 days total.

Budget: roughly $4,000–$5,000 for both of us.