I knew that would catch people. I try to link it in my mind with "vi" for "Vous" which is "you" in French and "ni" for "Nous" which is "we". "Li" is like "Lui" from Italian. and "Gee, what is it?" for ĝi which means "it". Luckily "ŝi" sounds like "she". http://en.wikipedia.org/wiki/Esperanto_grammar#Pronouns
Finishing a Duolingo tree doesn't make you fluent. On the CEFR, it probably brings you to A2 for most languages but as Esperanto is so easy to learn, you could probably expect it to take you up to B1, possibly. Finishing the tree generally isn't enough, you need to practice the language which can be done by visiting countries where the language is spoken by natives, using apps like Tandem to talk to native speakers or - in the case of Esperanto - going to conferences in your home country and practising speaking there. Duolingo is more a way into language learning than a zero-to-fluent tool.
Being an adjective, drunk ("bêbado") would need to end in "-a". According to Google translate, "trinkaĵo" (a noun) means beverage/"bebida" in portuguese. But drunk translates to "ebria" (pronnounced with 3 syllables: e-bri-a). And "ebrio", the noun, "intoxication". I'm not sure what "trinkaĵa" would mean, if it exists. Anyone knows?