Your Mercury is combust--swallowed up by the sun. For you, it's kind of like Mercury and the sun were the same. Sun's placement is about what your ego needs most for its own growth. Mercury in there, and in a Mercury ruled sign, gives it a clear Mercury message. So when you focus on your Mercury, you're also focusing on your sun.
Mercury's purpose is communication. In Virgo, it's about communication in some tangible form: written work, the arts, service... anything you might do that reaches or serves others.
Sun in Virgo needs to develop by developing skill, and it needs to be a useful skill, although the definition of useful is very broad. The skills you develop might be the kind you could make a living on, or might be "just" a hobby. It might be something that directly serves others, like teaching or fixing things or writing software, or it might be something you do for yourself that just so happens to result in something enjoyable for others, too. If you write, maybe you're doing it for yourself, but if anyone reads what you wrote, it reaches them. If you like playing sports or learning martial arts, whoever you learn and practice with gets to sharpen their skills, too. For example.
In the eighth house, the skills you develop are likely to fit an eighth house theme. Maybe you manage shared resources (which could include money, but not necessarily). Maybe you cook for large numbers of people (food is a shared resource, and cooking a skill to develop). Maybe you write fiction--that taps into the collective unconscious, which is an eighth house indication, and it's extremely common for writers to have significant Virgo placements. Maybe you create horror movies--that would fit the edginess of the eighth house.
At your age, those things are much more likely to be what you're considering than what you do, and maybe you're considering something else altogether. Whatever you end up doing for a career probably will fit the Scorpio/eighth house theme in some way, not only because of your sun and Mercury, but also because your midheaven is in Scorpio, and sextile your sun/Mercury, too.
That's just for starters, and not even touching on the Mars and Pluto aspects. Both of those planets are square your sun/Mercury by sign, but only Pluto is within orb of an actual square. Pluto is even more strongly Scorpio/eighth house than Mars, IMO.