Z Sagas
Movies
Where to watch
You can subscribe to Funimation or to watch it via streaming.
https://www.funimation.com/shows/dragon-ball-z/
You can purchase episodes or seasons from Amazon digitally.
https://www.amazon.com/dp/B01LYIOQ9P/?tag=era0f0-20
You can purchase the Blu-Rays or DVD's via Amazon.
https://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias=aps&field-keywords=dragon+ball+z+blu+ray
Where to read
You can purchase the manga digitally or physically at Viz Media.
https://www.viz.com/read/dragon-ball/section/31629/more