I failed my first time also. I used both Dion's videos on udemy and messer's on youtube as well as this book, https://www.amazon.com/dp/1260122042/ref=cm_sw_r_cp_apa_fabc_YFVUFb4EXMB97. Each one seemed to help me in different ways. Good luck on your test.
If you have access to a Safari online subscription you can get the CompTIA Network +. Good for basics and overview and its vendor agnostic.
https://learning.oreilly.com/library/view/comptia-network-certification/9781260122053/
If not and you want a physical copy you can get off amazon or a local store: