I didn't play the first one, about to play it for the first time after I finish a couple other games.
I absolutely loved this game and don't know really anything about the first game. Just the hour or so I played of it. I actually did notice something from that first hour in this game lol, so I know it must be pretty important all things considered. But I agree I didn't need to play the first game for this to be one of my favorite JRPGs I ever played.
This game is pretty much the same as any other game in a series. You almost never have to play a previous game in a series to enjoy the sequel. The previous game in the series typically enriches the experience you get with the sequel but it's almost never a required experience. Games are purposely written this way because many of them span different console generations so it leaves the previous game inaccessible to a lot of people.
The vast majority of games will recap enough of the plot of a previous game to get you up to speed enough to play. The exception of this is the Trails series if you play something like Trails SC or The 3rd and skip the previous game you'd be completely lost and the game isn't gonna recap jack shyt. Granted you could skip Trails in the Sky and play Cold Steel first and not be lost but the Trails series is the exception to the rule not the rule.
That being said Xenoblade 1 is way better than 2. People are doing themselves a disservice skipping 1. The plot and characters are way better. The blade system of 2 might be easier to get into though.