What are the standard parameters values for SMOTE technique?
First of all, if all your variables are numerical then you can you SMOTE; otherwise you should use SMOTENC.

Answers:
1- Your classes are 150-50, then SMOTE gives you 150-150. So, YES; your total dataset sample will be 300.

2- You can use the default parameters; it works well in most of the problems. However, you can play with random_state and k_neighbors. All parameters have been explained here: imblearn.over_sampling.SMOTE