Understanding the fasta File Format
Your understanding of FASTA format is about right. The type of basic problem you're eluding to we term &quot;sequence alignment&quot;- edit distance might be okay for teaching but in practise we use other algorithms, e.g. you might be interested in the Needleman–Wunsch or Smith–Waterman algorithms. Richard Durbin et al. wrote a great book that covers these any much more https://www.amazon.com/Biological-Sequence-Analysis-Probabilistic-Proteins/dp/0521629713
Tracking mutations etc. requires more than just alignment though, see &quot;phylogenetics&quot; (i.e. building genetic trees) and &quot;variant calling&quot;. Also checkout what the nextstrain team is doing https://nextstrain.org/ncov/global
In general, looking for practical applications for your algorithms is great, but be very careful before drawing any real world conclusions about the coronavirus outbreak from such analyses