Meetings are often used for the exchange of information — often from a senior person to a subordinate — or for discussion purposes. Decisions are often taken outside the meeting situation in a series of pre-meeting lobbying sessions. Thus, decisions which seem to be made within the meeting are often merely the ratification of a decision which has actually been made elsewhere.
Do not arrive at a meeting expecting an open decision-making process where people will commit to a particular course of action there and then. It is likely that issues will need to be taken away and discussed with certain other colleagues who are not present. You may need to be patient.
Once a decision has been taken, it will probably be seen as an interim step and that, should circumstances alter, the decision will probably need revisiting.
It would be reasonably unusual for junior people to openly disagree with more senior managers in the plenary of a full meeting but this does not mean, however, that people never disagree with the boss — they are just less likely to do so in front of other people.
Punctuality is variable in Portugal and it is possible that you can be kept waiting for some time — it is still advisable to arrive on time as this will be taken as a sign of respect and good intent. Agendas, if produced at all, will not necessarily be followed. It is felt that a meeting should be allowed to follow a natural path and that this approach is much more effective than being constrained by a pre-determined structure.