Proper wine bottles will require some sort of corking device.

Or if you buy beer bottles from the “HBS” or scrounge them from the local pub then you’ll still need a crown capping device (mine was less than a tenner) and some crown caps (bags of 50, can’t remember how much – not dear).

I’m guessing, but I wouldn’t suggest plastic pop bottles are such a good idea. Why? because they’re not really suitable for high % ABV liquid. Yes, they’re used for various ciders and beers, but those are all less than 10 % ABV, I’d guess that high % stuff may have a similar effect to putting petrol in a plastic (P.E.T. and/or Poly Carbonate) bottle i.e. it might not dissolve it like petrol would but I’d guess other probable degrading of the plastic i.e. perishing or becoming brittle.

Sticking your finger through the side of the plastic and spilling the contents is a waste of perfectly good booze.

Oh and you can sometimes see stuff on ebay and maybe even your local freecycle list.