how is to live there, job, cots of living, attractions, people...
Living in Glasgow you will be fine, I'm not sure what kind of job you'll be after but you'll find something. There's a huge Polish community so I imagine it wouldn't be too long before you meet other Poles and make some new friends :)
The cost of living is fairly high at the moment (everywhere in the UK is feeling the pinch) but it's OK. Food prices are going up (certainly in Scotland) and of course, fuel. Although, if your move is not immediate I wouldn't concern yourself with those things at the moment. Certainly if you're getting by in the US you should be fine here :)
Glasgow certainly has some great attractions but I'm not up to scratch on those so I won't go into them, but there is lots to do within the city but also plenty to visit outwith the city (like PD in Edinburgh ;). You won't be short of things to do on your days off or spare time, that is a certainty. Although, it does depend on your interests.
The people are fine. Really. Of course there are some idiots but you'll get that anywhere. As I said, there is an established Polish community in Glasgow but also many friendly Glaswegians.
It's a huge step if you are taking it. Your biggest transition might be the weather really ;)