about the new dataset and question

are there 50000 rows in the project 6 both data set because when i try to load the data its giving me error and can you pls give me any short summary or loom video on how to imputation the data i dont any thing about it should i use mean, median, mode and fill the most occurence or common data.and can i do this project in tableau because i have read the question and it mostly visualization of data.