TASK A AND TASK B DOUBT OF BANK LOAN CASE STUDY

I need help to perform some operations on task a and task b. Task A: Do i need to replace the missing data set with the average or median or replace it as Not Specified as we cant predict the data nd cannot put the data values on our own.Further, I dont know how to impute data using average or median. So I am a bit confused please help me. Task B: Do i just need to identify the outliers or also eliminate them? please help me abit to understand what is outliers and also how to approach this project?