Cycling UK Forum

I am planning, and hoping for a Cycle trip from the UK to Istanbul next May/June 2022.
Its a mixed picture.
In general you get 90 days in any 180 days to visit the EU as a Tourist.
However some Countries require you to have a separate Visa and are not included in the 90 days,Bulgaria for example.
There are COVID requirements, Tests and/or Negative Tests and Locator forms.
Thanks to Brexit and COVID things are more complex.

COVID restrictions allowing, cycling from Hook of Holland to Berlin in July.
Looking to do the E15 from Hook of Holland to Arnhem and then following the E2 to Berlin.
Camping for the most part.
Any tips?