Consider the fact that everyone will choose the progress of the OKRs (bottom-up model), but the decision to use the methodology must come from the top, otherwise it is very difficult to generate engagement in the team;
The size of the company counts a lot, small companies can reach all corners of the company with OKRs, but large corporations must work in a more targeted way (some boards reach more than 200 people, for example);
Key results must necessarily generate some kind of value for the company, either through progress or even development. Activities should not be considered key results;
OKRs can be corporate or individual. In the case of individual OKRs, the creation must follow the same model as corporate ones, but between employee and coach/manager;
In the first cycle, consider more attainable goals. The initial focus should be on traction and adaptation to the new goal management model.
Look for goal management tools, they will facilitate the entire implementation and monitoring process. The simpler it is to use, the less painful onboarding will be.