Get cables to a few points in the ceilings so you can put an access point there later.
If you are doing this, I’d also recommend getting a Power over Ethernet switch as well, ‘good’ access points can be powered via the network cable and it makes installs a lot neater as you don’t need a power socket close to your wifi access point, which can be a pain if it’s on the ceiling! While these access points come with their own power injectors usually, it saves another thing to plug in and wiring mess.
I’d also recommend picking a cubby hole somewhere (cupboard / loft / under the stairs etc) to act as the central point for all of your kit – somewhere that you can run all of your cables back to, put your switch etc. I’d have a pair of cables going from there to wherever your internet router is, and a pair going to each room where you want sockets. This gives you some future expansion and a back up in case something goes wrong with one of the cables.
I’d probably put cable drops to every room if I had the chance – even if you don’t plan on having them all connected up to start with, you always have the option for the future, and it’s pretty likely that more and more devices will need connections in the future.