If I login on a website using a vpn(let’s assume they have a software to detect what device I’m using) would a vpn be able to conceal my device information?
Nope, that’s a whole another thing. See coveryourtracks.eff.org. Honestly way harder to hide than your IP.
No, because there something called device and browser fingerprinting. Using privacy browsers like Brave or browser extensions that submit fake fingerprint data can help. Also customising browsers with themes, extra extensions etc make your device stick out like a sore thumb. Keeping browsers stock standard minimises this.
Vpn is totally operated through ip. Vpn doesn’t have concerns about the which device you are logged in. If you are using the router then they can detect which router you are using other wise only ip matters.
So use brave browser or DuckDuckGo g?