Upvote:0
You'll have to do your own legwork, but a simply Google search returns plenty of websites offering cycling holidays in Poland and, presumably access to experts.
Here are a few:
Upvote:3
Your profile says you live in Poland, so you should be aware that nice bikepaths don't exist here :) . However, I think you could try out some sea side area (should be pretty flat), SΕowiΕski Park Narodowy for example.
I've never been there, but heard about it to be nice bike-friendly area.