Like all Agora Models, Optimus Prime comes ready painted, so you do not need to paint any of the model.
Most construction will be by screwing parts together so there is little gluing involved, meaning that you will be able to achieve a professional, museum-quality finish to your model.
All-in-all construction of this model will require some dedicated time as there are approximately 600 parts, however you do not need to be an 'expert' modeller.