English does not use gender much. We usually indicate gender with extra words or context. You are correct: "I was with my friend drinking some shots" DOES NOT TELL US whether your friend is male or female. How do we solve the problem? With context. For example first names USUALLY imply gender. Rachel is a female name, Howard is a male name. If you say "I was with my friend Rachel drinking some shots," your friend must be female. If you say "I was with my friend Howard drinking some shots," we know your friend must be male. If you say "I was with my friend drinking some shots, and he said that..." we know he is male. A man's "girlfriend" implies romance. A woman's "boyfriend" implies romance. A man's "boyfriend" implies a (gay) romance. But, strangely, a woman's "girlfriend" could be just a friend. Animal names are tricky. There may be completely different words for the male, the female, and the young of the species. "I saw a bear and a baby bear in the zoo" is perfectly correct. "I saw a bear and a CUB in the zoo" is better. It gets very complicated. Many people do not know all the special names. It is correct to say "baby bear" or "female fox." A female fox (zorro) is a "vixen." A baby fox is a "kit." A male sheep (ovejo) is a "ram." A female sheep is a "ewe." (pronounced EXACTLY like the word "you"). A baby sheep is a "lamb." A male horse who is intact (non emasculado) is a "stallion." A male horse who has been castrated is a "gelding." A female horse is a "mare." A baby horse is a "colt." And on and on and on...

Thankfully, gender is not so important in English. A friend is a friend and it does not matter whether the friend is male or female, or of transitional or indeterminate gender. English verbs are not conjugated according to gender. If you wish to specify the gender, say "a male friend", "a female friend", or "a transgender friend".

Yes, gender really doesn't matter as much in English as in Spanish. In fact, job titles are becoming "neutral" so flight attendant, nurse and even actor and waiter can refer to males or females. If you really need to tell us the gender of the friend (and ask yourself: do you really need to?), then you can add "male/female" in front. You're right in thinking that "girlfriend" refers to your beloved, so "female friend" is possible, or even "one of the girls/women from my work/my uni/etc." Women can refer to their female friends as "girlfriends", but men would use "guy friend", "male friend" or even "mate" if the speaker is UK/Australian. For non-human things, including animals, we typically use "it". In your example, I'd actually write it as "a mother bear and her cub". Hope that helps a bit!