How often should I grease and repack my hubs and bottom bracket?
Looking at the spec of your bike it says the BB is a cartridge unit. This probably isn't serviceable -- it's designed to be replaced when worn out, so just keep riding it until it grinds or gets excessively sloppy.

The hubs might be serviceable. If you ride a lot in nasty conditions, or you're aggressive with the degreaser you might want to service them. However, if they're well-sealed (like most modern hubs and in particular Shimano hubs) then they almost never need servicing. If you're worried, learn how to service them yourself and see what they look like. If they're still packed with grease and nice and clean inside they don't need servicing. Servicing them isn't hard but it's a bit fiddly -- you'll lose a bearing under the fridge, then you won't be able to remember if there should be 9 or 10 balls, and whether they're 3/32" or 1/8" or 5/32", and so on. Don't do it for fun.

I ride a lot. My Campagnolo Neutrons have probably seen 10,000+ km. In that time I've had a look at the bearings once or twice. Still greasy, still smooth. The rims will wear out before the hub bearings do.