SMALL SWEET SIXTEEN PARTY IDEAS?!?
If you think 30 to 50 people is small, then I can't help you.
Is this a wedding or a sweet sixteen? See if you can trim it to 25/30 people-backyard or house party-pizza, cake, bowls of popcorn, potato chips and pretzels, bowls of mints and nuts, a few bowls of different -types of candy bars, soda and water and you are good to go without breaking the bank. Make it a beach theme-everyone loves the beach (mostly). Have some music going, a few good games, karaoke, scavenger hunt, or whatever you like - but do have prizes for the winners and some goodie bags to take home. Everyone will be happy.
Venues: Botanic garden, Hotel banquet room, Library banquet room, rent Disneyland for an evening, reserve a Public Park, rent a nice house/mansion Vacation Rental and have it in the house or the house backyard, city community center banquet room, ice skating ring, roller skating ring, movie theater banquet room, pool party, restaurant banquet room, rent a luxury yacht, country club banquet room, church recreation room. Food: Catered from a restaurant or fast food restaurant, pot luck, self prepared. Themes: Your favorite color, your favorite place, your favorite pastime/activity, your favorite character, balloons, bubbles, foam, candy. Activities: karaoke, dance floor, pictionary, family fued, scavenger hunt, trivia question game. Etc.: Give away prizes, give each guest a gift/party bag.