Where to start.... The simplest answer is "some other"
You can think of what DESeq does as kind of like a modified t-test on counts but the counts need to be normalized before you can use them. Istvan's answer here provides a great starting point: Does FPKM scale incorrectly in case of unequal mapping rates? as well as this post
Assuming you have a good understanding of NGS count data, you should also learn how linear modeling work. The user guide here is great for walking a beginner through how differential expression analysis works. edgeR is a tool similar to DESeq though there are some differences.