In 5th Edition there isn't much of a penalty for your familiar dying. You don't lose them permanently not do you take a health penalty. There might be material costs, I forget, but otherwise a familiar dying means very little.
In 5e, Find Familiar is a 1-hour spell, the ritual for which requires a brass brazier that you use to burn 10gp worth of charcoal, incense, and herbs. You need to perform this ritual to initially summon your familiar, to change its form, or to summon a new familiar if your old one dies. Most details about how familiars are summoned and used and what they can do are quite different in BG3.
