To answer your original question about the timeline, this may help.

A detailled version is here (not spoiler free!).

You can probably play the games in any order, but beware the first two are rather classics today, within the technical limitations of their time.

There’s also the Tales of two Wastelands mod, which combines FO3 and New Vegas on the latter’s engine. I’ve installed that, but admittedly was too lazy for a complete playthrough.