https://www.youtube.com/watch?v=oFdR_yMKOCw
Start at 3:41 if you just want the low-down on radiation and Rutherford’s experiment
Chapter 7.1 is all about Radiation and the 3 types of Radioactive decay. This video should help you understand the textbook explanation of the same.
Chapter 7.1 and 7.3 will be included in the midyear exam. Skip 7.2 on half-life.