During the consulate of the orator Marcus Tullius Cicero and C. Antonius- I'd rephrase this- While C & A were consuls
banished out of Rome from Cicero- banished from Rome by C
in the prison- in prison
defeated from Antonius- by
The logic goes weird at the end- he was banished in one sentence and killed in the next. =???
father in law Gaius Lelius,- father in law, Gaius Lelius,
in any occasion- on
toga virilis- I'd say something like 'was old enough to wear a toga', or give a footnote with a cultural explanation
learn by memory - by heart
addressing to Caesar’s legionaries words such as:- addressing Caesar’s legionaries with words such as:
How comes that you- How come you...
legio decima- the tenth legion
hit the horse’s chest - hit the horse in the chest