Beginner here trying to decide on system size

i was thinking 400W system but after reading and watching your videos not sure now, all i am looking to run is a laptop, lighting, smart phone charger, camera charger and some extra juice for the vehicle battery (not sure on last item)

Well you got to build for the worst. 4 days of heavy clouds in winter. And factor an inverter draws +/- ~1a at idle. 400w is basically a 20A battery charger. 1 hr a day to cover idle current.

I would say 400w would be good.

800 watts, 4 6v lead acid batteries or 2 100-120ah lithium and you're set. Unless your laptop is a 1080 Asus Strix running 16 hours then do the lithium at 800w and you might be fine without some generator time.

With the right charger you can trickle charge the vehicle battery (Bluesky 3000i has a 2 amp trickle, limited to 500w at the controller, or 400 not sure, Midnite Kid is 30amps with another controller connected to its load out can be programmed to send up to 30 amps through load out at current voltage).