You may pitch your tent for a night or two in the countryside as long as you don’t disturb the landowner or cause damage to nature.
It is important that you find a site that is well away from people’s houses and not on farmland. Choose hardy ground to pitch your tent, and avoid land used for grazing or for growing crops.
It is within the Right of Public Access to pitch two or three tents for a night or two. But a large group of people pitching large numbers of tents can cause problems with sanitation and damage to the ground. The landowner’s permission must be obtained in such cases.
In national parks and nature reserves there are special rules which may restrict the Right of Public Access. Tents are generally not allowed except in designated camping sites. In some areas tents are banned altogether.
You will find the rules posted in English on noticeboards around the area. You can also make inquiries from the local municipality or county administrative board.
Most municipalities have regulations about camping. The pitching of tents in places like parks or sports grounds may be banned. In general, camping that is allowed under the Right of Public Access is not restricted, but tents may be banned in outdoor recreation areas.
It is up to you to inquire about the local rules. The municipality and the police can give you the information you need.