"I am drinking a beer and you are eating an apple."
Translation:Je bois une bière et tu manges une pomme.
I am drinking. / I drink. → Je bois.
French does not use an auxiliary verb to express verbs in the present tense and there isn't a continuous present, per se. If it is really important to clarify that the action is occurring at this moment, you can write "Je suis en train de boire." This is essentially, I am in the middle of drinking. Most of the time though, the context is quite obvious to a francophone so they just say, je bois.
The general rule that words ending in a vowel are feminine has too many exceptions to be reliable. Your best bet is to memorize the article along with the noun. However, there are certain suffixes at the end of words which will give you a very good clue as to whether the word is masculine or feminine. This is page on noun genders in French will give you an excellent leg up.