As my car is on the stands and battery is out, I had a problem accessing my boot. When I want to push the ignition key in the lock, it just doesn't go there. It looks like, it's been blocked or something. Could it be because I had never use it before and it's just stuck and needs some oil, or is there some kind of trick?

Probably a seized lock. The service schedule should have included lubricating and exercising the locks annually - but of course the VAG service data is rubbish, inconsistent and does not address the design weaknesses of the vehicle.

Assuming you get the lock free, the boot can be opened manually (without power) by turning the key to one end of its rotational travel.

rotodiesel.

As my car is on the stands and battery is out, I had a problem accessing my boot. When I want to push the ignition key in the lock, it just doesn't go there. It looks like, it's been blocked or something. Could it be because I had never use it before and it's just stuck and needs some oil, or is there some kind of trick?

I would suspect that it due to lack of use they do tend to seize try the old WD40 using the key to try and draw it into the lock may take a while but it will come good