Hey dognie, good you are interested in webApp development. But when coming to hybrid app development mostly ionic you have to deal with angular.js, a MVC framework created by awesome people at google. So you have to learn and good at angular if you want build apps using ionic.

Coming to your question directly for ionic 1 you have to know angular 1. > and for ionic 2 you have to good at angular 2 comprises of Typescript and ES6 which recently moved out of beta, and you can start from angular2 there is no dependency on angular 1.

I would suggest Ionic 2. Specially if you are new to development. My suggestion is based a lot on the fact that you would be learning and using Angular 2 instead of Angular JS, and you would be able to write Typescript code instead of JS.