Welcome to the RTA forum!

We do have different classes of licenses in the US which is actually very similar to how you've described Finland's, but I'm sure you'll be able to drive a Trailblazer just fine with your current license. Basically, if you would be allowed to drive it over there, you would be allowed to drive it over here, and a Trailblazer weighs quite a bit less than 3500 kg.