Viewing Data/Drawing VOIs/Lesions
Now there are several different ways to do this, but I personally prefer using MRIcron because it is pretty easy to use and has good documentation. To familiarize yourself more with this program and how to view data, you can follow the tutorials linked below (which were excellently made by Dr. Jeremy Purcell). I know it is a pain when you can just watch the video, but actually following along and trying the activities will undoubtedly help you actually learn and get comfortable with viewing brain data.
Important Note
When viewing brain data, there are different coordinate systems used. This article covers all of them, but the most important ones (again, just in my opinion) to be familiar with are probably MNI, NIfTI, RAS, and FreeSurfer.