It depends on the gun in question.
If, for example, you have a Howa Type 89 (I know you don’t, this is a hypothetical), Tokyo Marui make possibly the most accurate airsoft replica of anything in the form of their GBBR version, which has identical weight, balance and handling to the real thing.
For AKs, LCT make stamped steel replicas which, with the dummy bolt setup, handle and weigh pretty much the same as a real AK.
However, there’s not that much that an airsoft gun lets you practice that you couldn’t just practice with the real thing if you already own it. If you want to familiarise yourself with the handling and operation of your gun, just use your gun. Clear it beforehand, and keep it pointed in the safest direction of course.