for たら, just add ら to the past tense た or だ form of a verb or adjective
たら is the only conditional that can be used for past events
shows that the past event was unexpected or surprising
ex: 「家に帰ったら彼がいた。」 means “When I returned home, he was there (and I was surprised to find him there).”
たら can also be used as a true conditional statement about future events
tends to emphasize what will happen if the condition is fulfilled (as opposed to れば which puts more emphasis on whether or not the condition will be fulfilled)
for なら, just put it after nouns or logical clauses
can be used with present or future conditions that are not in doubt
ex: 「彼なら、出来る。」 means “Since it’s him we’re talking about, it’s possible.”