Glassware: old-fashioneds, highballs, martinis, and wineglasses. Margarita and pint glasses are optional. For margaritas, just use old-fashioneds. And most people drink beer right out of the bottle or can. If safety is a concern, use plastic versions for the beach and poolside.
Accoutrements: wine opener, bottle opener, citrus juicer, long-handled spoon for muddling and stirring, cutting board, knife, cocktail shaker, ice bucket and tongs, jigger, and a book of concoctions. Bartenders are only as good as their tools. And the most important tools are good recipes! Yum.
Mixers and Garnishes: ginger ale, sparkling water, vermouth, superfine sugar, salt, cranberry juice, grenadine, Tabasco, bitters, Worcestershire sauce, olives, cocktail onions, cherries, mint, lemons, and limes.
Lucky you if you know a handyman/woman or you are one! (Can you build one for me?)