The alcohol & sugar contents vary depending on the product. Sherry & port are types of wine. Brandy is (I believe) a distilled beverage.
Wine, port & sherry can be made quite easily from kits or from fruits.
Proper brandy is illegal to make at home in the US & Canada. You can ferment a 20% alcohol using Turbo Yeast and then flavour the result with brandy essences.
Steve