Hi, sorry to hear of the troubles! Ok well, to start with the pistons, piston nr 1 must be at TDC, there is a mark in the crankshaft pulley (Driving the aux belt) which must line up with a mark on the plastic cambelt cover. then, as for the camshafts, you are going to need the cam lock tools, since no marks are present. I can more or less tell you in which position the lobes must be, but you need 100% accuracy here so that wont help. The lobes over cylinder 1 closest to the cam pulleys, should both face outwards (exhaust cam lobes facing to the front of the car, and inlet to the back)
As for the belt tension, the pic here shows where the little pin on the tensioner pulley should be, so with the pulley nut loosened, push the pin upwards, while also pushing the pulley against the belt so that it doesn’t slack. (If you don't have the required tools, two spanners should work) then fasten the nut. In the end, the pin must align with that little hole. The pic is for a 2.0 ts engine, so just ignore the smaller belt on front of the pulley, it's the balancing shafts' belt, which is not present in the 1.6
So not a though job, you just needs those cam locks though...hope this helps!