Loading CSV files from S3 into Redshift can be done in several ways. One of them is the COPY command which allows you to use SQL like commands to load the data into Redshift. This video demonstrates how to use COPY with key based access control or role based access control.
For loading CSV files from S3 into Redshift with AWS Glue check out my earlier video: https://www.youtube.com/watch?v=c5hWNEYp4g0