Wheel fitment

[Samuel bristow]

Hey guys need some help I’m looking at getting some new rims for my fr but I’m not sure what offset I need and I don’t even know what offset is lol just wondering if anyone can help me out as I was my wheels to sit flush with the arches but I want to lower the car in the future and don’t want any rubbing
Tia

 

[DavieTDI]

offset 50 is standard for your wheels but a think ya can go to 42 or is it 45 at 18" rims