First of all, Firefox Preview (code name Fenix) is Mozilla's effort to create a new mobile browser, so this is unrelated to which version of Firefox you run on your desktop.
Second, it's called Preview for a reason. Support for add-ons is currently being implemented, so if you install Firefox Preview on an Android device right now, you won't be able to use uBlock Origin yet.
Third, the built-in tracking protection blocks most ads (at least on websites I frequent EDIT: which do not include Google or Facebook etc.), so you can already try it out if you just want to see fewer ads and don't absolutely need uBlock Origin.
Second, it's called Preview for a reason. Support for add-ons is currently being implemented, so if you install Firefox Preview on an Android device right now, you won't be able to use uBlock Origin yet.
Third, the built-in tracking protection blocks most ads (at least on websites I frequent EDIT: which do not include Google or Facebook etc.), so you can already try it out if you just want to see fewer ads and don't absolutely need uBlock Origin.