This sounds extremely anal, but technically conjunctions aren't an aspect.
Aspect comes from ancient theory of sending/emitting light, or hurling the light rays at a planet. An aspect is like seeing one another so they form a relationship that way, and touching them with their light.
A conjunction is a corporeal union, a merging of two bodies, so it's treated very differently than an actual aspect. They merge their light, and their natures mix and mingle.
For a quick cheatsheet of aspects, check this out. Thema Mundi has been used as a teaching tool.
Cancer is set to the ASC because of summer solstice, its when the King/Queen of the heavens dominate with it being the hottest part of the year.
Sun-Venus is a sextile. The nature of the sextile is Venus.
Sun-Mars is square, nature of a square is that of Mars.
Sun-Jupiter is a trine, the nature of a trine is that of Jupiter.
Sun-Saturn is the opposition, the nature of it is that of Saturn.
Similar schema with the moon.