Help pls on building a system (comparability of various Ring devices)

Hi, I’m new to Ring products and want to build a camera / alarm system piece by piece, as funds allow!My question is do all Ring products work together ? For example our doorbell is a 2nd gen, so do I now have to buy other items that are also “2nd Gen”So far we have a 2nd gen doorbell and 3 x battery stick up cams and also a wired-in Floodlight ‘Plus’Next step feels like an alarm panel with motion/door sensors etc but I see these come in various options, 1st gen, 2nd gen etcI’d be really grateful to hear the advice of the wise ones - many thanks !