Yes, the num_training_steps is 750 sure.  The training_args are the default transformers that are at this link.
The code is:
from transformers import HfArgumentParser, Trainer, TrainingArguments

parser = HfArgumentParser((ModelArguments, DataTrainingArguments, TrainingArguments))
model_args, data_args, training_args = parser.parse_args_into_dataclasses()

P.s. ModelArguments contains the arguments pertaining to which model/config/tokenizer we are going to fine-tune from. While DataTrainingArguments contains the arguments pertaining to what data we are going to input our model for training and eval.