#1
im using a cheap classical guitar
after i strum a chord some strings are making like a metaly vibrating noise
its tuned in properly aswell it doesnt always happen either

is it my strumming or somthing ?

sorry if this is a stupid question
#2
nothing is stupid about wanting to learn, could be your not holding the strings down hard enough, or your E string is buzz the end of the neck, or maybe its cheap
Gear

Standard Epiphone LP W/Dimarzio Super 2's
1973 Ampeg VT-22

Fulltone Clyde
Ernie Ball VP Jr
Boss tu-2
Boss sd-1
Ehx Little Big Muff
Fulltone Ultimate Octave
Boss eq-7
Ehx Memory Man
Digitech Delay X-series
Ehx Holy Grail
#3
You need to have it set up by a luthier. The buzzing is your strings vibrating against some of the higher frets because the action is too low. This could either be the nut height, the neck relief, or the bridge height. You can do it yourself if you know what you're doing, but you're better off taking it somewhere.
Posted by: MSI
To get a 360 and a laptop to hook up all you have to do is get them drunk. They're pretty touchy feely.
#4
Does it also occur when a string is not fretted?
No? Then cdoaks may be right (though classicals normaly don't have adjustable truss rods, so neck relieve can probably be ruled out right away)
If it happens also when a string is not fretted at all, a too low an action can hardly be the problem. Instead there might be a problem with the top nut slots being slightly out of shape.
Or something else.
Truth is that things like this can even be hard to judge when actually holding and hearing the guitar. Diagnosing such problems over the internet is next to impossible, so I have to second cdoaks here and suggest you take it to a tech..