This guide touches content from three chapters of the Epp textbook Discrete Mathematics with Applications, but it is all revision of Year 1 material and if you are secure in this then you may wish to skip some parts of the reading. You can also use the Levin textbook Discrete Mathematics which is freely available online. There are also videos that will take you through the ideas.
The sections of this study guide match chapters in the Epp textbook. In Levin the material is found in Chapter 0 up to the end of Section 0.3 and in Section 3.1. The online version of Levin also has interactive questions to check your understanding.