Analyzing the results of a BLAST search, while similar, will depend on whether the original search was for a nucleotide or amino acid sequence.
Looking at the section "Sequences producing significant alignments" we see:
In either case, the items of interest are:
These results can be helpful in identifying what the searched sequence matches and what other species have similar substances.
Clicking on the name of any of the results will. again, display different results:
The results show the amino acid matches
The results show the alignment of the base pairs
Another form of searching is to compare 2 sequences to each other. The image below is from BLASTP, but the BLASTN has a similar facility. This is activated by clicking the "align two or more sequences" link:
Another interesting result is the report of the taxonomy tree of the significant matching sequences. Once again the results are similar for BLASTN and BLASTP. The example shown is from BLASTP:
Click on the "Distance tree of results" link.
The result is a visual tree of the matches. It is possible to get more details by clicking on one of the tree leaves: