Hi
Flying an ILS is an IFR technique that requires you to be able to fly 'on instruments'.
This means being able to fly using other instruments than the ILS readout. It is no good having the needles in the right place if you are in a 45 degree bank. If you are focusing on the ILS needles then you are not looking out of the window so need to have a good instrument cross check to remain at the correct attitude etc. All this is taught on an IR(R) course before starting on the ILS stuff for that reason.
Flying around on your own in the vicinity of an airfield practising an ILS without instrument flying tuition would be a VERY bad idea whether it is legal or not, which I am sure it isn't.
Do yourself a favour and get an IR(R). It will improve your flying and allow you to fly an ILS etc. If funds don't allow then stay VFR until you can afford it.