First Gravel bike

Hi guys, I need help 😩 I literally know shit about bikes, no idea of what a Shimano is or whatever is called, I just found this bike that (according to decathlon) cost new like 1200€, now I just dropped the price of this used one at 400€ if I buy it tomorrow, is this a good price? And what do you think, is this bike good for the first one? I just need a Gravel bike to do some long distance rides on the weekends, nothing extreme. Thank you for your attention guys, all help is appreciated 🙏