I'd say start with Xenoblade 1!

if you really wanna go down the rabbit hole, start with xenogears, then xenosaga episodes 1-3, then xenoblade. they are all sort of canon to each other.

What J said lol. IIRC X made some attempt at linking Xenoblade with the prior other Xeno series.

1 is a way better entry point in the series so you should start with this one.

its really up to you and what you care about, if an engaging story and a simple yet fun combat system with a small cast sounds good then 1 is where to start. but if you want freedom to explore everything in a mech and do tons of side quests then play x

As someone new to the series I'm playing 1 → X → 2 → DE → 3. Beat the first one already, highly recommend it.

Xenoblade Chronicles X is a spinoff, it doesn't really take place in the plot of 1 2 and 3

well I'll start with the 1 I don't have xc2 and xc3 at the time so I'll see