A FREILICHEN PURIM KOTON!!!
There's a disagreement if there's a requirement to eat a seuda on Purim Katan. Those that don't should at least eat or drink something extra during the day.
Even though we're celebrating the nes of Purim, we don't say Al Hanisim. One who mistakenly said it doesn't have to repeat. According to most there's no inyan to add any foods/drinks on Shushan Purim katan. Kiddush levana can be said tonight but just the bracha.