First put some high octane in your car, i.e. full tang main 500Rs ka high octane dalo. Knocking ghaib ho jayee gi.
My friend's vitz have the same issue and mechanic suggested that just start adding high octane and knocking is gone.
for CVT fluid you have to goto mechanic, i guess it costs around 3500 for genuine CVT fluid.
My mechanic told me if I had extra money then give him mutton karahi, but dont install iridium plugs. They will add zero performance gain to your vehicle. always stick with company stock plugs.
For Squal problem you have to 'face or phaze' your break plates. Squeel sound generally because of hard break pads or slipry break plates.
For mechanic, you can goto Ali, his shop is near 'Zia Balti & BBQ, Islamabad, Pakistan'. You can type that in google maps to get exact location.