How should I install the front wheel of a Muddyfox Bike (UK) This is my first bike ordered online and I don't have much experience in assembling. My problem is with the front wheel, which according to the assembly guide just fit into the fork.

However there are two nuts attached to the bolt which, as far as I understand can't be taken out and, the fork does not have enough space to "contain" both nuts.

Please see the images, on the left side the nut is between the bike and the fork but on the right side the nut and the fork are aligned so that the wheel moves no longer into the fork.

Any help?
The nuts you see are bearing cone and locknut, and they should not be removed unless you are servicing the bearings.

This kind of tolerances are something to be expected from bikes at this budget. Your options are to spread the fork by force, or since the bike is mail order, just return the whole thing.