>>1857981>which country or part of europe would you suggest for a first multi day trip?Go to any country or region you have a personal interest in.
>would you suggest individual route or someting like a Europaradweg?I think the Eurovelo routes are largely a meme. Don't think you'll be cycling on dedicated bike trails 100% of the time - the vast majority of the kilometers are along local roads with varying degrees of traffic. I think it's way more fun to make your own itineraries based on places you actually want to see but a part of a Eurovelo route might suit you just fine.
If you just want to get your feet wet consider one of Europe's many river bike trails. The stretch of the Danube bike trail between Passau and Vienna is quite famous for it's scenery. Can be extended to Budapest if you've got time to spare.
But again: If you're fascinated by the culture of the Basque country, the mountains and valleys of Graubünden or the history of Latgalia go there. Most of Europe is perfectly cyclable. Maybe not the Donbas right now.
>>1857989>Has anyone done any cycle touring around Finland's lakes? Yes. I think it's quite boring. Not sure why you'd want to go there coming from the UK. It will also be pretty cold in spring.