>>2280632I'm from Latvia, but my advice might be useful if you do the Baltic part.
You can camp in any forest freely as long as there is no signage stating that you are not allowed to or it doesn't look like someone's back yard. If you are asked to leave you must leave. No fires allowed (very strict rule, dry pine forests in summer burn like hay) from April to October. All of seacoast can be freely used for camping.
There's enough forest to sleep safely even if there were draconian laws against it (thankfully they are great for a EU country). Our countries have very low population density, so much of the country outside of the capital are 50k towns and small villages with a lot of forest inbetween. You will never be truly far away from civilization, but it will feel very empty. During the summer beaches have a lot of people, but it is very easy to find an empty beach even during peak summer. For example I used to live in a small sea side village and I had a more or less private beach all summer. Most people will just go to the main access point while there are huge sandy beaches almost everywhere along the coast. They are only broken up by rivers and docks, so you can mostly walk by the sea coast all throughout Latvian sea outline without breaking off.
Pic related.