I will suggest you to start with Bathrooms first. get the plumbing and water proofing checked. once you are clear that all the system is in place, depending on what look you want your bathrooms to be , you can consult an interior designer for material palate and designing. once your ideas are translated in drawings , you can get the civil and sanitary work done and you are good to go. For kitchen , just outsource it to modular kitchen guys, they will ask you your needs and how you want to set up your kitchen, they will take measurements and prepare a design / plans etc. and give you their material palate.. you can pick and choose your Colors and mood boards and within a month the assembling will be done and your kitchen will be ready.